JP2013168529A - Laser light source device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser light source device which easily performs visibility correction without using an expensive wavelength filter.SOLUTION: The laser light source device includes: a semiconductor laser 1 serving as a laser light source; a heat block 4 thermally connected with the semiconductor laser 1 and diffusing heat from the semiconductor laser 1; a heat pipe 5 where one end part is connected with the heat block 4 and a heat radiation fin 6 is provided at the other end part; and a fan 7 cooling the heat radiation fin 6. The laser light source device further includes: a first temperature sensor 8 and a second temperature sensor 9 that are disposed for measuring temperatures at two positions in the laser light source device; a control circuit 11 outputting a control signal for correcting the visibility from the output of the first temperature sensor 8 and the output of the second temperature sensor 9; and a driving circuit 12 driving the semiconductor laser 1 on the basis of the output of the control circuit 11.

Description

  The present invention relates to a laser light source device having a visibility correction function and an image display device including the laser light source device.

In recent years, in addition to conventional image display devices using discharge tubes, LEDs, etc., image display devices using a laser light source have been developed as consumer-use large-sized televisions or commercial large-sized displays.
This image display device forms image light by irradiating light from a light source onto a DMD (digital micromirror device) or the like as a modulation element by an illumination optical system, and this image light is screened by an optical system such as a lens or a mirror. The image is displayed by projecting it from the back or the like.
When a laser light source is used as the light source of such an image display device, the laser light source is coherent light having the same phase, and independent laser elements are R (red), G (green), and B (blue). ) Emits laser light in the wavelength band, etc., so it has higher energy-saving performance and a wider color reproduction range than conventional image projection devices (image display devices) using discharge tubes or LEDs. Is advantageous in that it is easy and the image rendering speed is fast, and is suitable for displaying 3D images (3D images).

The red laser light source is composed of a semiconductor laser that emits red wavelength laser light, and the green laser light source is composed of a wavelength conversion element, a solid-state laser crystal that oscillates its fundamental wave, and a semiconductor laser that excites the solid-state laser. In general, a laser resonator is used, and a blue laser beam source is a semiconductor laser that emits blue laser light.
However, in the semiconductor laser, the light emission efficiency and the oscillation wavelength change due to a change in temperature and a change in ambient temperature as the light output changes.
The sensitivity of the human eye depends on the oscillation wavelength. This is called visibility. In particular, the oscillation wavelength band of the laser light source is a band where the change in the visibility with respect to the wavelength change is remarkable.
For this reason, it is necessary to perform automatic power control (hereinafter referred to as APC) so that the visibility is constant even when the ambient temperature changes.

  International Publication No. WO2010 / 100898A1 (Patent Document 1) states that “a photosensor having a wavelength sensor having a characteristic such that a part of the light output of a laser light source is separated by reflection of a lens and approximately coincides with visibility. The light output separated by using is monitored, and APC is performed so that the visibility is constant even if the light emission efficiency and the oscillation wavelength change due to the light output temperature change and the ambient temperature change.

International Publication No. WO2010 / 100898A1

The wavelength filter used in the laser light source device described in Patent Document 1 or the like needs to have a wavelength characteristic that substantially matches the sensitivity of the human eye.
This wavelength filter has a problem (problem) that it is difficult to manufacture and costly.
In addition, when the wavelength characteristics of the wavelength filter vary, the brightness perceived by human eyes also changes, so it is important to solve this problem.
The present invention has been made to solve the above problems, and provides a laser light source device capable of easily correcting the visibility without using a wavelength filter, and an image display device using the laser light source device. The purpose is to do.

The laser light source device according to the present invention includes a semiconductor laser that is a laser light source, a heat block that is thermally connected to the semiconductor laser, and diffuses heat from the semiconductor laser, and one end is in contact with the heat block, In the laser light source device provided with a heat pipe provided with a radiation fin at the other end and a fan for cooling the radiation fin,
Viewed from the first temperature sensor and the second temperature sensor arranged to measure the temperature at two locations in the laser light source device, the output of the first temperature sensor, and the output of the second temperature sensor A control circuit that outputs a control signal for correcting sensitivity and a drive circuit that drives the semiconductor laser based on the output of the control circuit are provided.

The laser light source device according to the present invention is a laser light source device including a semiconductor laser that is a laser light source, a heat sink thermally connected to the semiconductor laser, and a fan that cools the heat sink.
Viewed from the first temperature sensor and the second temperature sensor arranged to measure the temperature at two locations in the laser light source device, the output of the first temperature sensor, and the output of the second temperature sensor A control circuit that outputs a control signal for correcting sensitivity and a drive circuit that drives the semiconductor laser based on the output of the control circuit are provided.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide easily the laser light source apparatus provided with the function which can correct | amend visibility without using a difficult and expensive wavelength filter.

1 is a diagram illustrating a configuration of a laser light source device according to Embodiment 1. FIG. It is a figure which shows the wavelength characteristic (specific visual sensitivity characteristic) of the sensitivity of human eyes. 3 is a flowchart showing APC of the laser light source device according to the first embodiment. It is a figure which shows the relative visibility characteristic normalized with the oscillation wavelength of 640 nm. It is a figure which shows the wavelength characteristic of the photodiode normalized by the oscillation wavelength of 640 nm. 3 is a graph of the proportionality constant α shown in Equation 1. 2 is a diagram showing a thermal circuit of the laser light source device according to Embodiment 1. FIG. It is a figure which shows the measurement result of the wavelength change by the temperature of a red laser light source. It is a figure which shows the structure of the laser light source apparatus by Embodiment 2. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the drawings, the same reference numerals indicate the same or equivalent ones.
Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a laser light source apparatus according to Embodiment 1 of the present invention.
A semiconductor laser 1 that is a laser light source includes a chip 1a that emits light and a stem 1b that diffuses heat generated by the chip 1a. The semiconductor laser 1 is thermally connected to a heat block 4 that further diffuses the heat generated from the semiconductor laser 1.
The heat of the heat block 4 is conducted to a heat pipe 5 having a bottom portion in contact with the heat block 4 and having heat radiating fins 6 at the ends.
Radiation fins 6 are provided at the ends of the heat pipe 5, and heat of the heat pipes 5 is conducted to the radiation fins 6, and the heat conducted to the radiation fins 6 is cooled by the fan 7 and exhausted. The heat radiating fins 6 and the fans 7 are provided in the duct 10.

A first temperature sensor 8 is disposed in close contact with the chip 1 a of the semiconductor laser 1, and a second temperature sensor 9 is disposed on the intake side of the radiating fin 6. That is, the first temperature sensor 8 is arranged so that the temperature of the chip 1a of the semiconductor laser 1 can be measured, and the second temperature sensor 9 can measure the temperature on the intake side of the radiating fin 6 (that is, the outside air temperature). Is arranged.
A part of the light output emitted from the semiconductor laser 1 is separated by the beam splitter 3, received by the photodiode 2, and converted into an electrical signal.

The control circuit 11 drives the laser light source (that is, the semiconductor laser 1) that makes the visibility constant from the electrical signal from the photodiode 2 and the electrical signals from the first temperature sensor 8 and the second temperature sensor 9. Calculate the current.
From this calculation result, the drive current of the semiconductor laser 1 is controlled by using the drive circuit 12, and the temperature of the chip 1a of the semiconductor laser 1 and the ambient temperature of the semiconductor laser 1 accompanying the change in the optical output (for example, intake air of the radiation fin 6). APC (automatic output control) is performed so that the visibility is constant even if the temperature on the side changes).
In FIG. 1, thick solid arrows indicate light output, broken arrows indicate electrical signals, and white arrows indicate wind flow.

FIG. 2 is a diagram showing the wavelength characteristics of sensitivity of the human eye (that is, specific luminous sensitivity characteristics) at 625 nm to 655 nm, which is the wavelength of red light.
Specific visual sensitivity is the numerical value of the intensity with which the human eye feels the brightness of each wavelength of light. The intensity at which the human eye feels the maximum sensitivity (555 nm) As 1 ”, the degree of feeling the brightness of other wavelengths is represented by a number of“ 1 ”or less so as to be the ratio.
As shown in FIG. 2, the relative visibility at a wavelength of 640 nm is 0.175, but the relative visibility at a wavelength of 630 nm is 0.266, which is about 1.5 times the relative visibility at a wavelength of 640 nm. The relative luminous sensitivity at a wavelength of 650 nm is 0.107, which is approximately 0.6 times the relative luminous sensitivity at a wavelength of 640 nm.

Therefore, when the oscillation wavelength of the semiconductor laser 1 changes from 640 nm to 650 nm, the brightness observed with the human eye is 1.5 times even if the optical output of the semiconductor laser 1 is constant.
When the oscillation wavelength is changed from 640 nm to 630 nm, the brightness observed with the human eye becomes 0.6 times.
Therefore, it is very important to correct the visibility with respect to the change of the oscillation wavelength in an image display device using a laser light source.
In the first embodiment, the case where the light emitted from the semiconductor laser 1 is red will be described. However, even in the case of a blue or green semiconductor laser, the visibility correction is performed by the laser light source device having the same configuration as in FIG. Can be done.

FIG. 3 is a flowchart showing APC of the laser light source device shown in FIG.
In the first embodiment, the oscillation wavelength λ of the laser light source (semiconductor laser 1) is calculated from the outputs of the first temperature sensor 8 and the second temperature sensor 9, and the laser light source is driven so that the visibility is constant. The current is controlled.
First, an optical output (for example, optical output at the time of shipment) I _ini and an oscillation wavelength (for example, an oscillation wavelength at the time of shipment) λ _{ini as a reference} are set (step S1). Usually, the light output I _ini of the laser light source is set so that the display image of the image display device has a standard brightness.

Next, in order to display an image, the laser light source (semiconductor laser 1) is turned on (step S2) and driving is started.
Thereafter, the temperatures measured by the first temperature sensor 8 and the second temperature sensor 9 are checked (step S3), and the oscillation wavelength λ of the laser light source is calculated (step S4).
The target light output I is calculated so that the brightness perceived by the human eye is the same by comparing the relative luminous sensitivity of the calculated oscillation wavelength λ and the specific luminous sensitivity of the oscillation wavelength λ _ini at the time of shipment (step S5).
Checking the temperature which the first temperature sensor 8 and the second temperature sensor 9 measures (step S3) substantially simultaneously checks the received light amount I _PD of the photodiode 2 (step S6).

As a result of comparing the target light output I in consideration of the oscillation wavelength λ and the received light amount I _PD of the photodiode 2, when I <I _PD (step S7), the drive current of the laser light source is increased (step S).
10) I = I _PD .
When I> I _PD (step S8), the drive current of the laser light source is decreased (step S11).
= I _PD . When I = _IPD (step S9), the process returns to the temperature sensor check (step S3) again while maintaining the laser light source drive current.
Steps S3 to S8 shown in FIG. 3 are executed by the control circuit 11 shown in FIG.
Steps S10 and S11 are executed by the drive circuit 12 shown in FIG.

The relationship between the “target light output I considering the oscillation wavelength λ” and “the light output I _ini of the reference laser light source” described in step S5 in FIG.
I = α × I _ini (Formula 1)
Here, α is a proportionality constant and is a function of the oscillation wavelength λ.
For example, the oscillation wavelength when the optical output I _ini of the reference laser light source is obtained is 640 nm.
In a semiconductor laser, the light emission efficiency and the oscillation wavelength change due to a change in temperature due to a change in light output and a change in ambient temperature.
Since the human eye has visibility, when the oscillation wavelength λ changes, even if the light output I is the same, the brightness perceived by the human eye is different.
Therefore, when the oscillation wavelength λ changes, the light output I of the laser light source changes so that the brightness perceived by human eyes is the same as the target light output I _ini set when the oscillation wavelength λ _ini is 640 nm. There is a need to.
Α described in Equation 1 is a correction coefficient at this time, and is a function of the oscillation wavelength.

Next, α is obtained.
When the relative visibility characteristic shown in FIG. 2 is normalized so that the vicinity of 640 nm is “1”, the graph shown in FIG. 4 is obtained.
FIG. 4 shows that when the oscillation wavelength is changed from 640 nm to 650 nm, the sensitivity of the human eye is about 1.5 times, and when the oscillation wavelength is changed to 630 nm, the sensitivity of the human eye is about 0.6 times. .

The photodiode 2 also has a wavelength characteristic similar to the human eye.
FIG. 5 shows an example of wavelength characteristics of the photodiode. FIG. 5 is normalized so that the visibility at a wavelength of 640 nm is “1”.
FIG. 6 shows the result of multiplying FIG. 4 and FIG.
FIG. 6 is a graph of the proportionality constant α shown in Equation 1.
When α in FIG. 6 is second-order approximated, it can be expressed as the following Expression 2.
α = 0.0015 × λ ^ 2-1.8162 × λ + 566.69 (Equation 2)
From Equation 2, if the oscillation wavelength λ is known, α can be calculated.
As a result, the target light output I in consideration of the oscillation wavelength λ can be calculated (step S5).

Next, details of the temperature sensor check (step S3) and the calculation of the oscillation wavelength λ (step S4) shown in FIG. 3 will be described.
FIG. 7 is a diagram showing a thermal circuit of the block diagram of the laser light source device shown in FIG.
In FIG. 7, Q _R is the calorific value of the chip 1a, T _j is temperature of the chip 1a, T _th is the measured value of the first temperature sensor 8, T _b is the temperature of the heat block 4, T _a second temperature The measured value of the sensor 9, R _j-th is the thermal resistance between the chip 1a and the first temperature sensor 8, R _th-b is the thermal resistance between the first temperature sensor 8 and the heat block 4, and R _b-a is The thermal resistance between the heat block 4 and the second temperature sensor 9, R _th-a, is the thermal resistance between the first temperature sensor 8 and the second temperature sensor 9.

From FIG. 7, the calorific value Q _R of the tip 1a can be expressed as Equation 3.
Q _R = (T _th -T _a ) / R _th-a (Formula 3)
Further, the chip temperature T _j can be expressed as shown in Equation 4.
T _j = T _a + Q _R × (R _j−th + R _th−a ) (Formula 4)
Substituting Equation 3 into Equation 4, the chip temperature T _j is expressed as Equation 5.
T _j = T _a + [(R _j−th + R _th−a ) / R _th−a ] × (T _th −T _a ) (Formula 5)

It is known that the temperature T _{j of the} chip 1a is proportional to the oscillation wavelength λ.
λ = A × T _j + B (Formula 6)
However, A and B are constants. When Expression 5 is substituted into Expression 6, the oscillation wavelength λ can be expressed as Expression 7.
λ = A ′ × T _a + A ″ × T _th + B (Formula 7)
However, A ′ = {1- × [(R _j-th + R _th-a ) / R _th-a ]} × A
A '' = [(R _j-th + R _th-a ) / R _th-a ] × A
From Equation 7, a constant A ', A' be previously measured ', measured value T _th and the first temperature sensor 8, using the measurement values T _a of the second temperature sensor 9, the oscillation The wavelength λ can be calculated.

FIG. 8 shows the first temperature when the light output of the laser light source is changed when the measured value Ta of the second temperature sensor 9 is 10 ° C., 18 ° C., 30 ° C. using the red semiconductor laser 1. The measurement value Tth of the sensor 8 and the result of measuring the oscillation wavelength λ at that time are shown.
From the measurement result of FIG. 8, constants A ′, A ″, and B in Expression 7 are as shown in Expression 8.
From the characteristics of the semiconductor laser, it was experimentally found that A ″ and A ′ described in Expression 7 are values between A ″: 0.2 to 0.5 and A ′: −0.4 to 0.
λ = 0.34 × T _th -0.15 × T _a +631.17 (Equation 8)

From these results, the APC control flow shown in FIG. 3 is performed every certain period, so that the APC can keep the visibility constant even if the temperature change or the ambient temperature changes due to the light output change. Can be realized.
Since this method does not use the wavelength filter described in Patent Document 1, it can be easily realized at low cost.
In the first embodiment, the first temperature sensor 8 is disposed in the chip 1a of the semiconductor laser 1 or in close contact with the chip 1a, and the second temperature sensor 9 is disposed on the intake side of the radiating fin 6 in the duct 10 ( That is, it was arranged between the heat radiation fin 6 and the fan 7).
It should be noted that the first temperature sensor 8 and the second temperature sensor 9 can obtain the same effect even if they are disposed at two arbitrary locations as long as they are located between the chip 1a and the radiation fin 6 on the intake side.
In the present embodiment, the first temperature sensor 8 and the second temperature sensor 9 are respectively provided at two locations on the intake side of the semiconductor laser 1 that is the heat generation source and has the highest temperature and the radiation fin 6 that has the lowest temperature. By arranging and making the difference between the measurement results of the first temperature sensor 8 and the second temperature sensor 9 larger, the influence of the measurement error of the temperature sensor can be reduced.

As described above, the laser light source device according to the first embodiment includes the semiconductor laser 1 that is a laser light source, the heat block 4 that is thermally connected to the semiconductor laser 1 and diffuses the heat from the semiconductor laser 1, and one end. In a laser light source device including a heat pipe 5 having a portion in contact with the heat block 4 and having a heat radiating fin 6 at the other end and a fan 7 for cooling the heat radiating fin 6, two temperatures in the laser light source device The first temperature sensor 8 and the second temperature sensor 9 arranged for measuring the temperature, and the control signal for correcting the visibility from the output of the first temperature sensor 8 and the output of the second temperature sensor 9 And a drive circuit 12 for driving the semiconductor laser 1 based on the output of the control circuit 11.
With this configuration, since the oscillation wavelength can be estimated from the outputs of the two temperature sensors, visibility correction can be realized at low cost without using an expensive wavelength filter that is difficult to manufacture.

The first temperature sensor 8 of the laser light source device according to the first embodiment is arranged at a position where the temperature of the semiconductor laser 1 can be measured, and the second temperature sensor 9 is the fan 7 side of the radiating fin 6 (measures the outside air temperature). It is arranged at a position where it can be done.
With this configuration, the temperature difference between the two temperature sensors (that is, the first temperature sensor 8 and the second temperature sensor 9) becomes the largest. Therefore, the influence of the measurement accuracy of the temperature sensor can be suppressed to the maximum, and the accuracy of the visibility correction is improved.

Further, the laser light source device according to the first embodiment, by using the measurement value (T _th) and the measurement value of the second temperature sensor 9 of the first temperature sensor 8 (T _a), the linear equation (lambda = A " Estimate the oscillation wavelength λ from × T _th + × T _a + B) to correct the visibility.
With this configuration, the oscillation wavelength is estimated from the outputs of the two temperature sensors (that is, the first temperature sensor 8 and the second temperature sensor 9). Therefore, the visibility can be corrected at a low cost without using a wavelength filter.

Embodiment 2. FIG.
FIG. 9 is a configuration diagram of a laser light source apparatus according to Embodiment 2 of the present invention.
The semiconductor laser 1 includes a chip 1a that emits light and a stem 1b that diffuses heat generated from the chip 1a.
The semiconductor laser 1 is thermally connected to a heat sink 13 that diffuses heat generated from the semiconductor laser 1, and is cooled using a fan 7 that cools the heat sink 13. The semiconductor laser 1 and the heat sink 13 are provided with a first temperature sensor 8 and a second temperature sensor 9, respectively.

Also in the second embodiment, the procedure for calculating the oscillation wavelength λ of the semiconductor laser 1 from the temperatures measured by the first temperature sensor 8 and the second temperature sensor 9 and performing APC so that the visibility is constant is as follows: The procedure is the same as that described in the first embodiment.
In FIG. 9, components that achieve the same functions as the components of FIG. 1 showing the configuration of the laser light source device according to the first embodiment are denoted by the same reference numerals.
Also in the second embodiment, by performing the control flow of APC shown in FIG. 3 at a certain period, it is possible to realize APC in which the visibility is constant even when the ambient temperature changes. It becomes possible.

Similarly to the first embodiment, this embodiment can be realized at low cost because it does not use an expensive wavelength filter which is difficult to manufacture as described in Patent Document 1.
In the second embodiment, since the semiconductor laser 1 is attached to the heat sink 13 without the heat pipe 5, the apparatus becomes compact.

  In the first embodiment or the second embodiment described above, the case where the semiconductor laser 1 is red has been described. However, even if it is a blue or green semiconductor laser, the laser light source device having the same configuration as in FIG. 1 or FIG. Thus, it is possible to realize visibility correction.

As described above, the laser light source device according to the second embodiment includes the semiconductor laser 1 that is a laser light source, the heat sink 13 that is thermally connected to the semiconductor laser 1, and the fan 7 that cools the heat sink 13. In the light source device,
Viewed from the first temperature sensor 8 and the second temperature sensor 9 arranged to measure the temperature at two locations in the laser light source device, the output of the first temperature sensor 8 and the output of the second temperature sensor 9 A control circuit 11 that outputs a control signal for correcting sensitivity and a drive circuit 12 that drives the semiconductor laser 1 based on the output of the control circuit 11 are provided.
According to this configuration, the oscillation wavelength can be estimated from the outputs of the two temperature sensors without using a wavelength filter, and it is not necessary to provide a heat pipe or a heat radiating fin. Can do.

Also in the second embodiment, the first temperature sensor 8 is disposed at a position where the temperature of the semiconductor laser 1 is measured, and the second temperature sensor 9 is disposed on the fan 7 side of the heat radiation fin 6.
Therefore, it is possible to estimate the oscillation wavelength from the outputs of the two temperature sensors without using an expensive wavelength filter which is difficult to manufacture, and it is not necessary to provide a heat pipe or a heat radiating fin, so that the laser light source device is made compact. be able to.
Furthermore, since the temperature difference between the two temperature sensors (that is, the first temperature sensor 8 and the second temperature sensor 9) is the largest, the influence of the measurement accuracy of the temperature sensor can be suppressed, and the visibility correction can be performed. Accuracy is improved.

Embodiment 3 FIG.
The laser light source device according to the first embodiment or the second embodiment can be used as a laser light source of an image display device that emits a plurality of laser beams of R (red), G (green), and B (blue).
For example, Patent Document 1 (International Publication No. WO2010 / 100898) is an image display device having a laser light source device and means for spatially modulating laser light emitted from the laser light source device and projecting it onto a screen. A plurality of laser light source devices are provided, and each of the plurality of laser light source devices emits laser light of each primary color (that is, R, G, B), and synthesizes the plurality of laser light from the plurality of laser light source devices. An image display device is further described which further includes a combining unit, and the spatially modulated laser beam is a laser beam combined by the combining unit.

The image display device according to the third embodiment replaces the laser light source device according to the first or second embodiment with each primary color (instead of the laser light source device using the wavelength filter as described in Patent Document 1). It is used as a laser light source device for emitting R, G, B) laser light.
Specifically, the image display device according to the third embodiment spatially modulates the laser light source device according to the first or second embodiment that does not use the wavelength filter, and the laser light emitted from the laser light source device. And three laser light source devices, each of which emits a laser beam of each primary color and three laser light sources. The apparatus further includes a combining unit that combines the three laser beams from the apparatus, and the spatially modulated laser beam is a laser beam combined by the combining unit. Therefore, in the image display device according to the present embodiment, the laser light source device is difficult to manufacture and an expensive wavelength filter is not used, so that the cost of the image display device can be reduced.

  The present invention is useful for realizing a laser light source device having a visibility correction function without using a wavelength filter that is difficult to manufacture.

DESCRIPTION OF SYMBOLS 1 Semiconductor laser 1a Chip 1b Stem 2 Photodiode 3 Beam splitter 4 Heat block 5 Heat pipe 6 Radiation fin 7 Fan 8 1st temperature sensor 9 2nd temperature sensor 10 Duct 11 Control circuit 12 Drive circuit 13 Heat sink

Claims (6)

A semiconductor laser that is a laser light source; a heat block that is thermally connected to the semiconductor laser and diffuses heat from the semiconductor laser; one end is in contact with the heat block, and a heat dissipation fin is provided at the other end In the laser light source device provided with a heat pipe and a fan for cooling the radiation fin,
A first temperature sensor and a second temperature sensor arranged to measure two temperatures in the laser light source device;
A control circuit for outputting a control signal for correcting visibility from the output of the first temperature sensor and the output of the second temperature sensor;
A laser light source device comprising a drive circuit for driving the semiconductor laser based on an output of the control circuit.   The said 1st temperature sensor is arrange | positioned in the position which measures the temperature of the said semiconductor laser, The said 2nd temperature sensor is arrange | positioned at the said fan side of the said radiation fin, The Claim 1 characterized by the above-mentioned. Laser light source device. Using the measured value (T _th ) of the first temperature sensor and the measured value (T _a ) of the second temperature sensor, oscillation from _a linear equation (λ = A ″ × T _th + A ′ × T _a + B) The laser light source device according to claim 1, wherein the visibility is corrected by estimating the wavelength λ. In a laser light source device comprising a semiconductor laser that is a laser light source, a heat sink thermally connected to the semiconductor laser, and a fan that cools the heat sink,
A first temperature sensor and a second temperature sensor arranged to measure two temperatures in the laser light source device;
A control circuit for outputting a control signal for correcting visibility from the output of the first temperature sensor and the output of the second temperature sensor;
A laser light source device comprising a drive circuit for driving the semiconductor laser based on an output of the control circuit.   5. The first temperature sensor 8 is disposed at a position where the temperature of the semiconductor laser is measured, and the second temperature sensor is disposed on the fan side of the heat sink. Laser light source device. An image display device comprising: the laser light source device according to any one of claims 1 to 5; and a projection unit that spatially modulates the laser light emitted from the laser light source device and projects the light onto a screen. ,
Three of the laser light source devices are arranged, and each of the three laser light source devices further includes a combining unit that emits laser light of each primary color and combines the three laser light from the three laser light source devices. The image display device characterized in that the spatially modulated laser beam is a laser beam synthesized by the synthesizing means.

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