JP2014112124A - Light source device and projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of appropriately activating a laser diode under a temperature condition lower than a lower limit value of operation temperature of the laser diode.SOLUTION: When the power is turned ON, the temperature of a laser diode 1 is detected by a temperature sensor 4, and a CPU 32 determines whether the detected temperature is lower than a lower limit operation temperature of the laser diode 1. When the temperature of the laser diode 1 is determined lower than the lower limit operation temperature, a red LED 14 and a blue LED 17 are driven to emit light to heat the laser diode 1 with the heat generated by the LEDs 14 and 17. When the laser diode 1 is heated and reaches or exceeds the lower limit operation temperature, the CPU 32 controls the laser diode 1 to be constantly lit.

Description

  The present disclosure relates to a light source device, and more particularly to a light source device used in a projection display device.

  Conventionally, as a light source device of a projection display device, one using a high-pressure mercury lamp has been mainstream, but recently, as disclosed in Patent Document 1, a phosphor is excited by light emitted from a laser diode, The thing using the light fluorescently emitted from the fluorescent substance has been developed.

  However, the operating temperature range of the laser diode is provided, and if it is started in a temperature environment lower than the lower limit of the operating temperature range, even if it can be started, there is a possibility that the laser diode may be undesirably affected. there were.

JP 2011-134668 A

  The present disclosure provides a light source device capable of appropriately starting a laser diode even in an environment having a temperature lower than the lower limit value of the operating temperature of the laser diode.

  The light source device according to the present disclosure includes a first light emitting element having a first lower limit operating temperature, a temperature detecting unit that detects a temperature of the first light emitting element, a heating unit that heats the first light emitting element, and a temperature. Temperature information from the detecting means is input, and temperature measuring means for measuring the temperature of the first light emitting element and control means are provided. When the temperature measuring means determines that the temperature of the first light emitting element is lower than the first lower limit value, the control means causes the heating means to raise the temperature of the first light emitting element to the first lower limit operating temperature or higher. After that, the first light emitting element is driven.

  According to the present disclosure, even if a light emitting element such as a laser diode is in an environment where the temperature is lower than the lower limit operating temperature, the light emitting element can be started after the lower limit operating temperature is reached. It is possible to contribute to the improvement of the lifetime of the light emitting element, and consequently the reliability of the light source device using the light emitting device and the display device using the light source device.

FIG. 3 is a schematic diagram illustrating a projection display apparatus according to the first embodiment. FIG. 3 shows a main part of the light source device according to the first embodiment. FIG. 3 is an explanatory diagram of a light source device according to Embodiment 1. FIG. 3 is a main part block diagram of the projection display apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an operation flowchart regarding the first embodiment. FIG. 6 is a schematic diagram showing a projection display apparatus according to Embodiment 2. FIG. 10 is a main part block diagram of a projection display apparatus according to a second embodiment. FIG. 10 is a diagram illustrating an operation flowchart regarding the second embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

The inventor provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.
(Embodiment 1)
The first embodiment will be described below with reference to FIGS.

  FIG. 1 is a diagram showing a configuration of a projection display device 100 using the light source device according to the embodiment.

  In FIG. 1, reference numeral 1 denotes a laser diode (LD) that emits blue light for excitation, and a plurality of these laser diodes 1 are arranged in a matrix 2 in a holder 2 to constitute an excitation light source. The holder 2 is formed of a material having excellent heat conductivity, and a cooling module 3 is disposed on the back surface thereof.

  Reference numeral 4 denotes a temperature sensor disposed in the holder 2. The temperature sensor 4 detects the temperature of the laser diode 1. As the temperature sensor 4, for example, a temperature detection element such as a thermistor can be used.

  Reference numeral 5 denotes a collimator lens formed by collimating the excitation light (blue light) of the laser diode 1, and reference numeral 6 denotes a condenser lens that condenses the blue light output from the collimator lens 5. Reference numeral 7 denotes a lens that receives blue excitation light emitted from the condenser lens 6 and converts it into parallel light.

  The excitation blue light emitted from the lens 7 passes through a dichroic mirror 8 that transmits blue light and reflects green light, and enters a condensing / parallelizing lens 9 including a pair of convex lenses 9a and 9b.

  The blue light incident on the condensing / collimating lens 9 is applied to the green phosphor 102 formed as a phosphor layer by being applied to the phosphor wheel 101 of the phosphor wheel device 10 whose details are shown in FIG. 3 is condensed to excite the green phosphor 102. The phosphor wheel device 10 is configured to rotationally drive the phosphor wheel 101 by a motor 103. As a result, the phosphor is prevented from being burned by the blue excitation light collected there.

  2B is a side view of the green phosphor 102 taken along the line A-A ′ in the plan view of FIG.

  The green light that is excited by the excitation light and emitted from the green phosphor 102 of the phosphor wheel 101 enters the condensing / parallelizing lens 9 and is collimated and emitted to the dichroic mirror 8.

  The dichroic mirror 8 reflects the green light from the condensing / parallelizing lens 7 and emits the green light to the dichroic mirror 12 that transmits green and reflects red.

  Reference numeral 13 denotes a collimating lens composed of a pair of convex lenses 13a and 13b, and reference numeral 14 denotes a red LED (light emitting diode) that emits red light arranged opposite to the collimating lens 13. Red light from the red LED 14 is collimated by the collimating lens 13 and emitted to the dichroic mirror 12.

  The red light emitted from the collimating lens 13 is reflected by the dichroic mirror 12 and enters the dichroic mirror 15 that transmits the red light and the green light and reflects the blue light.

  Reference numeral 16 denotes a collimating lens composed of a pair of convex lenses 16a and 16b. Reference numeral 17 denotes a blue LED (light emitting diode) which is arranged opposite to the collimating lens 16 and emits blue light. Blue light from the blue LED 17 is collimated by the collimating lens 16 and emitted to the dichroic mirror 15.

  In this manner, the green light from the phosphor wheel device 10 is reflected by the dichroic mirror 8 and then passes through the dichroic mirrors 12 and 15 and enters the condenser lens 18. Red light emitted from the red LED 14 is reflected by the dichroic mirror 12, passes through the dichroic mirror 15, and enters the condenser lens 18. Blue light emitted from the blue LED 17 is reflected by the dichroic mirror 15 and enters the condenser lens 18.

  The condensing lens 18 condenses the green light, red light, and blue light and emits them to one end surface of the rod integrator 19. Light emitted from the other end surface of the rod integrator 19 passes through the relay lenses 20 and 21 and is emitted to the total reflection mirror 22.

  The light reflected by the total reflection mirror 22 passes through a lens 23 and enters a DMD (Digital Mirror Device) 24. The DMD 24 modulates incident light with a video signal and outputs the modulated light to the projection lens 25 through the lens 23. The projection lens 25 enlarges and projects the incident light onto a screen (not shown).

  FIG. 4 is a principal circuit block diagram of the projection display apparatus according to the present embodiment. A video signal from an external video source (for example, a personal computer) is input to the input terminal 30 and supplied to the video signal processing circuit 31. Is done.

  Reference numeral 32 denotes a microcomputer (CPU) that performs various controls. The video signal processing circuit 31 performs video processing such as scaling processing of the video signal input under the control of the CPU 32, and outputs a drive signal to the DMD drive circuit 33 that drives the DMD 24. The DMD driving circuit 33 receives the driving video signal from the video signal processing circuit 31 and controls the DMD 24, whereby the light from the light source is modulated according to the video signal, and the modulated video light is converted into the projection lens 25. Is projected on a screen (not shown).

  A power circuit 34 is controlled to be turned on or shut down by the CPU 32, and power is supplied from the power circuit 34 to each circuit block of the projection display device.

  A laser diode drive circuit 35 is controlled by the CPU 32 and drives the laser diode 1 to emit light. Reference numeral 36 denotes a laser diode drive detection unit that detects the light emission drive state of the laser diode 1 and supplies the detection output to the CPU 32.

  A laser diode temperature detector 37 detects a temperature value obtained by the temperature sensor 4, converts the detected value into a digital signal, and supplies the digital signal to the CPU 32.

  Reference numeral 38 denotes an LED drive circuit that drives the red LED 14 and the blue LED 17 to emit light under the control of the CPU 32. Reference numeral 39 denotes an LED drive detection unit that detects the light emission drive state of the red LED 14 and the blue LED 17 and supplies the detection output to the CPU 32.

  Although not shown in the block diagram of FIG. 2, the CPU 32 also performs drive control of the phosphor wheel device and other controls.

  Next, the control operation by the CPU of the projection display device at a low temperature will be described with reference to the flowchart of FIG.

  When the power of the projection display device is turned on (S1), the CPU 32 measures the temperature of the laser diode 1 from the temperature information obtained from the laser diode temperature detection unit 37, and from the low temperature driving guarantee lower limit (S / D threshold). It is determined whether it is low (S2).

  The S / D (shutdown) threshold is an air temperature (or a temperature of the projection display device) at which the projection display apparatus can start projection within a predetermined time T after the power is turned on. In the present embodiment, the S / D threshold value is minus 2 degrees (-2 ° C.), and if the temperature is up to minus 2 degrees, the heating operation described later enables projection within a predetermined time T. Guarantee that you can. In the present embodiment, the predetermined time T is set to 5 minutes.

  In step 2 (S2), if the temperature of the laser diode 1 is equal to or higher than the S / D threshold (−2 ° C.), the process proceeds to the next step 3.

  In step 3 (S3), the temperature of the laser diode 1 is measured from the temperature information obtained from the laser diode temperature detecting unit 37, and the lower limit value (W-up threshold value) of the operating temperature determined by the manufacturer's specifications. ) A determination is made as to whether: The operating temperature range of the laser diode 1 used in the present embodiment has a lower limit operating temperature value of 0 ° C. and an upper limit operating temperature value of 60 ° C. If the laser diode is used outside this operating temperature range, the laser diode may be damaged. Therefore, it is necessary to use the laser diode within this range.

  If it is determined in step 3 (S3) that the temperature of the laser diode is 0 ° C. or higher, in step 4 (S4), the CPU 32 drives the laser diode 1, red LED 14, and blue LED 17 and ends the lighting operation.

  If it is determined in step 2 (S2) that the temperature of the laser diode 1 is lower than the S / D threshold (−2 ° C.), the process proceeds to the next step 5.

  In step 5 (S5), since the temperature of the laser diode 1 is lower than the S / D threshold value (−2 ° C.), the laser diode cannot be turned on within 5 minutes by the heating operation by the LED described later. Therefore, the warning display LED provided in the cabinet of the projection display device is turned on to notify the user that the lighting state will not be turned on within 5 minutes, and the power supply of the projection display device is shut down (S6).

  In step 3 (S3), the temperature of the laser diode 1 is measured from the temperature information obtained from the laser diode temperature detector 37, and the temperature of the laser diode 1 for excitation is the lower limit value (W-up threshold) of the operating temperature. If it is determined that the temperature is lower than 0 ° C., the warm-up operation of Step 7 (S7) is performed. The warm-up operation in the present embodiment is an operation for driving the red LED 14 and the blue LED 17 to emit light, and the air in the projection display device or the device itself is heated by the radiant heat generated from the LED at the time of light emission. As a result, the laser diode 1 is also heated. The value of the lower limit operating temperature of the LED is minus 20 degrees (−20 ° C.), which is lower than that of the laser diode, and can operate even when minus 2 degrees.

  When the warm-up operation is started, it is measured how long the operation has been performed (S8), and if it is determined that the warm-up operation has continued for more than 5 minutes, for some reason It is determined that projection is not possible within 5 minutes after the power is turned on, and the same treatment as that when the threshold is lower than the S / D threshold is performed, that is, a warning is displayed in step 5 (S5), and the power is turned on in step 6 (S6). Shut down.

  If it is determined in step 8 (S8) that the warm-up operation is 5 minutes or less, it is determined in step 9 (S9) whether the temperature of the laser diode 1 is lower than 0 ° C. which is the lower limit operating temperature. The If the temperature is lower than the lower limit operating temperature in step 9 (S9), the process returns to the warm-up operation in step 7 (S7) and the warm-up operation is continued.

  When the temperature of the laser diode 1 is measured from the temperature information obtained from the laser diode temperature detection unit 37 in step 9 (S9), and the temperature of the laser diode 1 is determined to have risen to the lower limit operating temperature or higher, In step 4 (S4), the laser diode 1 is driven to emit light for projection together with the red LED 14 and the blue LED 17.

  As described above, in the present embodiment, the configuration from the excitation laser diode 1 to the relay lens 21 shown in FIG. 1 and the CPU 32, power supply circuit 34, laser diode drive circuit 35, and laser diode drive shown in FIG. The detection unit 36, the laser diode temperature detection unit 37, the LED drive circuit 38, and the LED drive detection unit 39 constitute a light source device of a projection display device.

  In this way, in this embodiment, the red LED and the blue LED are caused to emit light and the laser diode is heated, so that the laser diode can be operated even at low temperatures without providing special parts for heating the laser diode. It can drive suitably.

  The laser diode drive detection unit 36, the laser diode temperature detection unit 37, and the light emitting diode drive detection unit 39 can also be configured by software functions of the CPU 32.

(Embodiment 2)
Next, the second embodiment will be described with reference to FIGS.

  For convenience of explanation, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 is a diagram showing a configuration of a projection display device 200 using the light source device according to the present embodiment. In the second embodiment, a heater 40 is attached to the back surface of the cooling module 3. Further, as shown in FIG. 7, the heater 40 is driven by a heater drive circuit 41 controlled by the CPU 32, the driving state of the heater 40 is detected by the heater drive detection unit 42, and the detection output is input to the CPU 32. It has become. The heater drive detection unit 42 can also be software of the CPU 32.

  With this configuration, when the heater 40 is heated, the heat of the heater is transmitted to the laser diode 1 through the cooling module 3 and the holder 2 by heat conduction, and the laser diode 1 is heated.

  FIG. 8 is a flowchart of the control operation of the CPU 32 according to the second embodiment. The same control steps as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  That is, in the present embodiment, in step 3 (S3), the temperature of the laser diode 1 is measured from the temperature information obtained from the laser diode temperature detector 37, and the temperature of the pumping laser diode 1 is the operating temperature. If it is determined that the temperature is lower than 0 ° C. which is the lower limit value (W-up threshold value), the warm-up operation of Step 77 (S77) is performed.

  The warm-up operation in step 77 of the present embodiment is an operation in which the heater 40 is driven to generate heat by the heater drive circuit 41, and the heat generated by the heater 40 is transmitted to the laser diode 1 by heat conduction and heated.

  As described above, in the present embodiment, the configuration from the excitation laser diode 1 to the relay lens 21 shown in FIG. 6 and the heater 40 and the CPU 32, the power supply circuit 34, the laser diode drive circuit 35, shown in FIG. The laser diode drive detector 36, the laser diode temperature detector 37, the LED drive circuit 38, the LED drive detector 39, the heater drive circuit 41, and the heater drive detector 42 constitute a light source device of the projection display device.

  In this embodiment, the laser diode can be directly heated and the heating power is strong, so that the laser diode can be driven in a short time. That is, there is an advantage that the L / D threshold can be considerably lowered.

  As described above, Embodiments 1 and 2 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to an embodiment in which changes, replacements, additions, omissions, and the like are appropriately performed. Moreover, it is also possible to combine each component demonstrated in the said Embodiment 1 and 2 into a new embodiment.

  As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present invention can be applied to, for example, a projection display device including a light source device.

DESCRIPTION OF SYMBOLS 1 Laser diode 4 Temperature sensor 6 Condensing lens 8 Dichroic mirror 10 Phosphor wheel apparatus 12 Dichroic mirror 14 Red LED
15 Dichroic mirror 17 Blue LED
18 Condensing lens 19 Rod integrator 24 DMD
25 Projection lens 32 CPU
40 heater 102 green phosphor

Claims (6)

A first light emitting device having a first lower operating temperature;
Temperature detecting means for detecting the temperature of the first light emitting element;
Heating means for heating the first light emitting element;
Temperature information from the temperature detection means is input, and temperature measurement means for measuring the temperature of the first light emitting element;
When the temperature measuring means determines that the temperature of the first light emitting element is lower than the first lower limit value, the heating means causes the temperature of the first light emitting element to be equal to or higher than the first lower limit operating temperature. Control means for driving the first light emitting element after being raised;
A light source device comprising:   2. The light source device according to claim 1, wherein the heating unit is a second light emitting element having a second lower limit operating temperature lower than the first lower limit operating temperature.   The light source device according to claim 1, wherein the heating unit is a heater.   3. The light source device according to claim 2, wherein the first light emitting element is a laser diode, and the second light emitting element is a light emitting diode.   5. The phosphor substrate according to claim 4, wherein a phosphor substrate that emits first color light by excitation light emitted from the laser diode is provided, and the light-emitting diode includes a first light-emitting diode that emits second color light, and a third light-emitting diode. A second light emitting diode for emitting colored light, and comprising: a light combining means for combining the first, second, and third color lights; and a light emitting means for emitting the light combined by the light combining means. A light source device.   6. The light source device according to claim 1, a light modulation device that modulates light from the light source device according to a video signal, and projection that projects light from the light modulation device on a screen. A projection display device comprising: an optical device.

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