WO2013118258A1

WO2013118258A1 - Light emitting module and light emitting device

Info

Publication number: WO2013118258A1
Application number: PCT/JP2012/052856
Authority: WO
Inventors: 大志辻
Original assignee: パイオニア株式会社
Priority date: 2012-02-08
Filing date: 2012-02-08
Publication date: 2013-08-15

Abstract

[Problem] To provide a light emitting device and a light emitting module that can reduce luminance fluctuations and reduce the amount of an increase in voltage consumption. [Solution] In the present invention the following are provided: a current adjusting unit connected in parallel via a switch to at least one light emitting panel which emits light using luminance according to a supplied current value based on power supply, and for adjusting the current value supplied to the light emitting panel; a voltage measuring unit for measuring the voltage applied, based on the power supply, to the light emitting panel; and a switch control unit for turning the switch on or off in accordance with the applied voltage that was measured.

Description

Light emitting module and light emitting device

The present invention relates to a light emitting module and a light emitting device having a light emitting panel.

Conventionally, a light emitting device having a plurality of light emitting panels is known (for example, Patent Document 1). For example, it is conceivable that a plurality of surface-emitting type light emitting panels such as organic EL (Electro Luminescence) are arranged in a plane and the light emitting device is used as illumination.

JP 2008-97994 A

By the way, normally, when one of the plurality of light emitting panels fails, the light emitting panel is replaced with a new light emitting panel. In general, the longer the light emission time, the lower the luminance of the light-emitting panel. Therefore, the luminance of the existing light-emitting panel is lower than that of a new light-emitting panel. Therefore, when the same current is supplied to all the light-emitting panels, luminance variation occurs. However, simply providing a configuration for lowering the supply current to a new light-emitting panel than the supply current to an existing light-emitting panel increases the current consumption by the amount of current consumed by the configuration.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a light emitting module and a light emitting device that can suppress an increase in current consumption while reducing luminance variation after replacing a light emitting panel. .

A light emitting module according to the present invention is a light emitting module including at least one light emitting panel that emits light with luminance according to a supply current value based on power supply, and is connected in parallel to the light emitting panel via a switch, A plurality of current adjusting sections for adjusting the supply current value to the light emitting panel; a voltmeter side section for measuring an applied voltage to the light emitting panel based on the power supply; and the switch according to the measured applied voltage. And a switch control unit that controls on / off of the switch.

The light emitting device according to the present invention is a light emitting device including a plurality of light emitting panels connected in series and a power supply unit that supplies power to each of the light emitting panels. One of the light emitting panels, which is connected in parallel to one light emitting panel via a switch and each adjusts a supply current value based on the power supply to the one light emitting panel. And a voltmeter side section that measures an applied voltage based on the power supply, and a switch control section that controls on / off of any of the switches according to the measured applied voltage.

It is a block diagram which shows the structure of the light emitting module which is an Example of this invention, and a light-emitting device. It is a table | surface which shows the relationship between the ratio of the variable resistance of a current adjustment part, the resistance of a light emission panel, and a panel lighting rate. It is a table | surface which shows the relationship between the cumulative light emission time about a light emission panel, an applied voltage rise value, and a luminance maintenance factor. 3 is a flowchart showing a luminance variation adjustment routine in the configuration of FIG. 1. It is a block diagram which shows the structure of the light-emitting module and light-emitting device which further include an attachment detection part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the configuration of the light emitting modules 10-1 to 10-n (n is an integer of 2 or more) and the light emitting device 20 of the present embodiment.

The light emitting module 10-1 includes a light emitting panel 1-1, a current adjusting unit 2-1, a switch 3-1, a voltmeter side unit 4-1, and a switch control unit 5-1.

The light-emitting panel 1-1 emits light with luminance according to the supply current value based on the power supply from the power supply unit 6. The light emitting panel 1-1 is a surface light emitting panel such as an organic EL. The light emitting panel 1-1 may include a plurality of light emitting panels connected in parallel to each other.

The current adjusting unit 2-1 is connected in parallel to the light emitting panel 1-1 via the switch 3-1. The current adjustment unit 2-1 is a variable resistor, for example. When the switch 3-1 is in the on state, a part of the current supplied to the light emitting panel 1-1 flows to the current adjusting unit 2-1, and as a result, the value of the current supplied to the light emitting panel 1-1 is adjusted. It is also possible to finely adjust the value of the current supplied to the light emitting panel 1-1 by changing the variable resistance value. The variable resistance value can be changed manually.

The resistance value of the current adjusting unit 2-1 is larger than the resistance value of the light-emitting panel 1-1 (hereinafter referred to as panel resistance value), and is preferably 1 to 20 times the panel resistance value.

The voltmeter side unit 4-1 measures the applied voltage based on the power supply from the power supply unit 6 to the light emitting panel 1-1.

The switch control section 5-1 controls on / off of the switch 3-1 according to the applied voltage measured by the voltmeter side section 4-1. Specifically, the switch control unit 5-1 switches the switch 3-1 from on to off when the applied voltage exceeds a predetermined specified value.

Each of the light emitting modules 10-2 to 10-n has the same configuration as the light emitting module 10-1. The light emitting panels 1-1 to 1-n are electrically connected in series.

The power supply unit 6 supplies power to each of the light emitting panels 1-1 to 1-n connected in series.

FIG. 2 shows the relationship between the resistance ratio between the variable resistance value of the current adjusting unit 2-1 and the panel resistance value, and the panel lighting rate of the light-emitting panel 1-1. The panel lighting rate is a ratio when the luminance of the light emitting panel 1-1 when the switch 3-1 is in the off state is 100%. For example, when the variable resistance value is four times the panel resistance value, the panel lighting rate is 70%. The relationship shown in FIG. 2 is similarly established for the light emitting panels 1-2 to 1-n and the current adjusting units 2-2 to 2-n.

FIG. 3 shows the relationship between the cumulative light emission time, the applied voltage increase value, and the luminance maintenance rate for the light emitting panel 1-1. The applied voltage increase value and the luminance maintenance rate in FIG. 3 are measured values when the organic EL light-emitting panel is driven at a current density of 20 mA / cm 2. It can be seen that the applied voltage increases almost in proportion to the cumulative light emission time. Further, as can be seen from the fact that the luminance maintenance ratio is, for example, 79% when 400 hours elapse and 70% when 825 hours elapses, the degree of decrease in the luminance maintenance ratio becomes moderate as time elapses. The relationship shown in FIG. 3 holds similarly for the light emitting panels 1-2 to 1-n.

Hereinafter, the operation of the light emitting device 20 when the light emitting panel 1-1 fails and is replaced will be described with reference to FIGS. 1 to 3 together with FIG.

First, the light emitting panel 1-1 is replaced (step S11). For example, the light emitting panel 1-1 is replaced when the current luminance of each of the light emitting panels 1-1 to 1-n reaches 80% of the initial luminance.

Next, the amount of current supplied to the light emitting panel 1-1 is adjusted (step S12). In the case of the above example, the variable resistance value of the current adjusting unit 2-1 is set to four times the resistance value of the light emitting panel 1-1. With this setting, the panel lighting rate of the new light emitting panel 1-1 is 80% (see FIG. 2). Such adjustment eliminates the luminance variation between the existing light emitting panels 1-2 to 1-n and the new light emitting panel 1-1. Note that when the replacement is completed, the switch 3-1 is in the on state, and a part of the current supplied to the light emitting panel 1-1 flows to the current adjusting unit 2-1. Is reduced to 80%.

The voltmeter side section 4-1 constantly measures the voltage applied to the light emitting panel 1-1 after the panel replacement. The switch control unit 5-1 determines whether or not the applied voltage measured by the voltmeter side unit 4-1 exceeds a predetermined specified value (step S13). The specified value is set as a value that is larger than the applied voltage immediately after the panel replacement by a predetermined set value. For example, when the applied voltage immediately after the replacement of the panel is 5V, 5.08V that is larger than this by 0.08V can be set as the specified value.

When the applied voltage exceeds the specified value, the switch controller 5-1 turns off the switch 3-1. Accordingly, the supply current does not flow into the current adjustment unit 2-1, and the adjustment of the supply current amount for the light emitting panel 1-1 is finished (step S14). In the case of the above example, when the current applied voltage increases by 0.08 V from the applied voltage immediately after the panel replacement, the adjustment of the supply current amount is finished. Hereinafter, the increase in the applied voltage is referred to as a voltage increase value.

The voltage applied to the light-emitting panel 1-1 after the switch 3-1 is turned off is a value obtained by multiplying the voltage increase value by {(panel resistance value + variable resistance value) / variable resistance value}. When the variable resistance value is set to four times the panel resistance value as described above, the voltage increase value of the applied voltage for the light emitting panel 1-1 is 0.1 V (= 0.08 V × 5/4). . In this case, the luminance maintenance rate of the light-emitting panel 1-1 is 77% (see FIG. 3).

In this case, 465 hours have passed since the panel replacement (see FIG. 3). Further, the panel replacement is performed when the panel lighting rate of the new light-emitting panel 1-1 becomes 80%, that is, after about 370 hours have elapsed since the light-emitting device 20 is started. In addition, the intermediate point of 340 hours and 400 hours which are the cumulative light emission times corresponding to the luminance maintenance rates of 81% and 79% in FIG. 3 is 370 hours. Therefore, the accumulated light emission time of each of the existing light emission panels 1-2 to 1-n is about 835 hours (= 370 hours + 465 hours) from the time of activation of the light emitting device 20 when the panel is replaced. In this case, the luminance maintenance rate of each of the existing light emitting panels 1-2 to 1-n is about 70% (see FIG. 3).

As described above, when the adjustment of the supply current amount for the light emitting panel 1-1 is completed, the luminance maintenance rate of the light emitting panel 1-1 is 77%, and each of the light emitting panels 1-2 to 1-n is The luminance maintenance rate is about 70%. The luminance variation of each of the light-emitting panels 1-1 to 1-n is within 10%, which is within an unnoticeable level.

As described above, in the light emitting modules 10-1 to 10-n and the light emitting device 20 according to the present embodiment, the current supplied to the light emitting panel 1-1 is reduced for a while after the replacement of the light emitting panel 1-1. Decrease the luminance. By such an operation, the luminance variation between the existing light emitting panels 1-2 to 1-n is reduced, and the uncomfortable appearance can be eliminated.

Generally, when an organic EL light emitting panel is used as a lighting device, the luminance is often set low to obtain soft light. When the set luminance is low, the luminance variation is easily noticeable. In such a case, the present invention is particularly effective.

Further, when the applied voltage for the light emitting panel 1-1 exceeds a predetermined specified value, the adjustment of the supply current to the light emitting panel 1-1 is finished. With this operation, after the luminance variation of the light emitting panels 1-1 to 1-n is reduced, current consumption in the current adjustment unit 2-1 and the switch 3-1 that perform the adjustment can be reduced. If a time measuring unit is provided for each light-emitting panel in order to end the adjustment of the current supplied to the light-emitting panel after a certain time has elapsed, a microcomputer is required to configure the measuring unit and the cost is increased. Will lead to. On the other hand, in the present invention, paying attention to the fact that the cumulative light emission time of the light emitting panel and the applied voltage to the light emitting panel are in a proportional relationship, the light emitting panel when the applied voltage exceeds a predetermined specified value The adjustment of the supply current to is terminated. With this configuration, it is possible to reduce current consumption after adjusting the supply current while suppressing costs.

Further, as shown in FIG. 5, the light emitting modules 10-1 to 10-n may further include attachment detecting units 7-1 to 7-n. The attachment detection unit 7-1 detects that the light emitting panel 1-1 is attached to the light emitting device 20 when the panel is replaced, and supplies a detection signal to the switch control unit 5-1. The attachment detection unit 7-1 includes, for example, a mechanical operation mechanism such as a switch (not shown) that is pressed when the light emitting panel 1-1 is attached to the light emitting device 20, and detects according to the operation. It can be configured to output a signal. The switch control unit 5-1 turns on the switch 3-1 according to the detection signal. With this configuration, when the light-emitting panel 1-1 is attached to the light-emitting device 20, the switch 3-1 is automatically turned on and the supply current to the light-emitting panel 1-1 is adjusted. Each of the attachment detection units 7-2 to 7-n has a function similar to that of the attachment detection unit 7-1. Each of the switches 3-2 to 3-n has a function similar to that of the switch 3-1.

The above examples are all examples in which the light emitting panel 1-1 is replaced, but similar effects can be obtained by the same operation when any of the light emitting panels 1-2 to 1-n is replaced.

1-1 to 1-n Light emitting panel 2-1 to 2-n Current adjustment unit 3-1 to 3-n Switch 4-1 to 4-n Voltmeter side unit 5-1 to 5-n Switch control unit 6 Power supply Supply unit 7-1 to 7-n Mounting detection unit 9-1a to 9na, 9-1b to 9-nb Terminal 10-1 to 10-n Light emitting module 20 Light emitting device

Claims

A light-emitting module including at least one light-emitting panel that emits light with luminance according to a supply current value based on power supply,
A plurality of current adjustment units connected in parallel to the light-emitting panel via a switch and adjusting the supply current value to the light-emitting panel;
A voltmeter side for measuring the voltage applied to the light emitting panel based on the power supply;
A light-emitting module, comprising: a switch control unit that controls on / off of the switch according to the measured applied voltage.
The light emitting module according to claim 1, wherein the switch control unit switches the switch from on to off when the applied voltage exceeds a specified value.
It further includes a replacement detection unit that detects that the light emitting panel has been replaced,
The light emitting module according to claim 2, wherein the switch control unit turns on the switch in response to the detection.
The light emitting module according to claim 2, wherein the current adjusting unit is a variable resistor.
The light emitting module according to claim 2, wherein the light emitting panel is an organic EL light emitting panel.
A light emitting device including a plurality of light emitting panels connected in series, and a power supply unit that supplies power to each of the light emitting panels,
A current adjusting unit that is connected in parallel to a corresponding one of the light emitting panels via a switch, and each adjusts a supply current value based on the power supply to the one light emitting panel;
A voltmeter side that each measures an applied voltage based on the power supply to any of the light emitting panels;
A light-emitting device, comprising: a switch control unit that performs on / off control of any one of the switches according to the measured applied voltage.