JP2009086272A - System for starting projection type video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To actuate a semiconductor laser element array that is a light source after achieving laser operation set temperature when starting a projection type video display device, thereby shortening an idling time of the device and also protecting the semiconductor laser element array from thermal effect. <P>SOLUTION: A light source unit is constituted by arranging a plurality of light source elements constituted by disposing the semiconductor laser device array where a plurality of semiconductor laser devices are arranged on the same substrate on a heat receiving plate and disposing an electric heater and a temperature detection means (temperature sensor) for the semiconductor laser device array on the heat receiving plate hierarchically so that light beam may be guided to the irradiation surface of a synthetic prism for each of three primary colors. The heat receiving plate of the light source element is connected to a cooling means, and the electric heater and the temperature sensor are connected to a control means. The control means compares temperature detected by the temperature sensor with the predetermined laser operation set temperature, thereby determining the actuation time of the semiconductor laser device array. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a startup system for a projection display apparatus (projector) that generates projection light by modulating and synthesizing laser light of at least three primary colors according to image information, and projects an image on a screen via a projection lens. Is.

  In many conventional projection display apparatuses, a discharge lamp such as a metal halide lamp or an ultra-high pressure mercury lamp is used as a light source for generating light of the three primary colors. The emitted white light is separated into three primary colors of red (R), green (G), and blue (B) by a dichroic mirror, and the three primary colors are modulated by image information and synthesized by a synthesis prism (dichroic prism), and then projected. The image is displayed on the screen through the lens.

  In order to respond to the demand for higher brightness (higher output) in a projection display apparatus that employs such a discharge lamp, it has been attempted to employ a high output discharge lamp or to increase the number of lamps. Yes. However, such countermeasures increase the amount of heat generated from the discharge lamp, so that the cooling structure increases in size, and measures such as noise and increase in the size of the power source are indispensable. Since the emission spectrum of a discharge lamp has a peak in yellow, it is necessary to use red or green mixed with yellow in order to effectively use the emitted light. Therefore, there is a problem that the color purity of the generated single color is poor and high color reproducibility cannot be realized. In addition, the discharge lamp has a problem that it is necessary to take measures to compensate for the light quantity in the red wavelength band because the light quantity in the red wavelength band is not sufficient compared to the light quantity in the green and blue wavelength bands in the emission spectrum. It was.

  In spite of these problems, projection display devices that employ discharge lamps have recently become increasingly demanding for larger images projected on screens in the business market, etc. Increasing the amount of light emission is a problem. However, there is a limit to increasing the output of the light source, and at the same time, there is a problem that an increase in the amount of light that can be used effectively cannot be realized due to a decrease in efficiency when a plurality of light sources are used. Therefore, in order to solve the problem in the case where the above-described discharge lamp is employed, an attempt has been made to employ a semiconductor laser element array as an element of a light source particularly intended to increase output (see Patent Document 1). .

  In this semiconductor laser element array, for example, several tens of semiconductor laser elements are monolithically arranged on the same semiconductor substrate at a high density, and light emission spots corresponding to the number of arrays are formed. I try to do it. When such a semiconductor laser element array is employed, it is an important issue to keep the laser operation set temperature constant in order to stably oscillate each semiconductor laser element of the semiconductor laser element array.

When the laser operation set temperature fluctuates, the light emission output from the semiconductor laser element array fluctuates, which affects the result of color synthesis and shortens the lifetime. Therefore, in the technique disclosed in Patent Document 1, a Peltier element and a heat sink are combined to cool the semiconductor laser element array. Further, as another means for forcibly cooling the semiconductor laser element, there is one in which a cooling medium passage is arranged in parallel to each semiconductor laser element from the cooling device so as to be cooled to a predetermined temperature ( Patent Document 2).
JP 2007-201285 A Japanese Patent Laying-Open No. 2005-026575

  When a semiconductor laser element is used as a light source, it can be turned on and off instantaneously as compared with the case where a discharge lamp is used, and has a characteristic that color reproducibility is wide and life is long. However, as the temperature of the semiconductor laser element rises, the light emission efficiency decreases and the crystal defects increase. Along with this, the ratio of non-emissive transition increases, so even in the transition mechanism that operates as the original light emission principle, heat is generated, the temperature of the element rises, and the light emission capability decreases at an accelerated rate, and the operating temperature If you don't manage it, it will lead to a shortened lifespan.

  The present invention is premised on a configuration for synthesizing three primary colors emitted from a semiconductor laser element array in which a plurality of semiconductor laser elements having such optical properties are arranged. Is provided with characteristics that are greatly affected by temperature, and when the temperature of the element changes, the wavelength, luminance, and emission spot diameter of the emitted light change. When such a state is reached, the white balance is lost.

  Therefore, the semiconductor laser element array must be constantly maintained at a constant laser operation set temperature at which stable operation is maintained. For example, a semiconductor laser device can obtain a high output at a temperature relatively lower than room temperature (about 20 ° C.) and can maintain a long life, so that the laser operation set temperature is kept constant regardless of how the environmental temperature changes. A cooling means for maintaining the temperature is necessary, and it is ideal to keep the temperature within a range of ± 1 ° C., for example.

  However, the cooling means disclosed in Patent Document 1 has a composite structure of a Peltier element and a heat sink, and the peripheral portion of the light source element is complicated and large, so that a plurality of semiconductor laser element arrays are provided for each of the three primary colors. It is not possible to employ the light source element having a configuration in which the individual semiconductor laser element arrays are temperature-controlled. Further, in the cooling means disclosed in Patent Document 2, it is difficult to grasp the temperature state of each semiconductor laser element, and an extremely large-scale apparatus that includes an individual means for adjusting the flow rate of the cooling refrigerant, Become.

  As described above, there is a problem to be further solved in the projection display apparatus using the semiconductor laser element array in which consideration for temperature is important as a light source. In other words, the conventional cooling means as described above is based on the assumption that the projection display apparatus has been started and has reached a stable state, and does not take into consideration thermal problems at the start of the apparatus. Absent. As is well known, the semiconductor laser element itself is a heat source, and the temperature of the semiconductor laser element at the time of start-up is assimilated with the environmental temperature when installed indoors. Even when the cooling means starts operation, the emitted semiconductor laser element instantaneously reaches a temperature higher than the ambient temperature until a predetermined cooling capacity is obtained.

  In such a state, since the semiconductor laser element array greatly deviates from the laser operation set temperature, it does not become a steady light emission state, and accurate color gradation expression cannot be performed, which causes a shortened life. Therefore, by shortening the time required for starting the apparatus and operating the semiconductor laser element array at the laser operation set temperature as much as possible, the idling time of the apparatus at the start-up is shortened and the semiconductor laser element array is heated. There will be no negative impact.

  The present invention provides a light source unit arranged in a hierarchy so that a plurality of light source elements each having a semiconductor laser element array arranged on a heat receiving plate are guided to the irradiation surface of the synthesis prism for each of the three primary colors. In the projection type image display apparatus provided, the semiconductor laser element array can rapidly reach the laser operation set temperature as the apparatus starts up, and then the semiconductor laser element array can be operated to shorten the idling time of the apparatus. Another object of the present invention is to realize protection of the semiconductor laser element array at the same time.

  Therefore, the present invention solves the above problems by means described below. In other words, the invention according to claim 1 is a projection type video display apparatus in which projection light is obtained by modulating and synthesizing laser light of three primary colors with image information, and a plurality of semiconductor lasers on the same substrate. A plurality of light source elements each including a semiconductor laser element array in which elements are arranged are disposed on a heat receiving plate, and an electric heater and temperature detecting means (temperature sensor) of the semiconductor laser element array are disposed on the heat receiving plate. The light source units are arranged in a hierarchy so as to be guided to the irradiation surface of the synthesis prism for each primary color, and the light source element is connected to the cooling means, and the electric heater and the temperature sensor are connected to the control means. The operation timing of the semiconductor laser element array is determined by comparing the temperature of the temperature sensor with a preset laser operation temperature by the control means. That as to the activation system.

  According to a second aspect of the present invention, in the start-up system for the projection display apparatus according to the first aspect, when the temperature detected by the temperature sensor is equal to or higher than the laser operation set temperature, the cooling means is immediately driven to drive the semiconductor laser. The temperature of the element array is lowered, and then the semiconductor laser element array is activated when the temperature sensor detects the laser operation set temperature.

  According to a third aspect of the present invention, in the start-up system of the projection display apparatus according to the first aspect, when the temperature detected by the temperature sensor is equal to or lower than the laser operation set temperature, the semiconductor laser element array is immediately formed by the electric heater. When the temperature rises, on the other hand, when the temperature detected by the temperature sensor exceeds the laser operation set temperature, the cooling means is driven and the semiconductor laser element is cooled to the laser operation set temperature. Activate the element array.

  According to a fourth aspect of the present invention, there is provided a projection display apparatus in which projection light is obtained by modulating and synthesizing laser beams of three primary colors with image information, and a plurality of semiconductor laser elements are arranged on the same substrate. A plurality of light source elements each having an arrayed semiconductor laser element array disposed on a heat receiving plate and an electric heater and a temperature sensor disposed on the heat receiving plate are guided to the irradiation surface of the composite prism for each of the three primary colors. As described above, the light source units are arranged in a hierarchical manner, the light source elements are connected to the cooling means, and the electric heater and the temperature detecting means (temperature sensor) of the semiconductor laser element array are connected to the control means, When the temperature detected by the temperature sensor is equal to or higher than the laser operation set temperature, the cooling means is immediately driven to lower the temperature of the semiconductor laser element array, and then the temperature sensor is When the laser operating set temperature is detected, the semiconductor laser element array is activated, and after the semiconductor laser element array is activated, the maximum temperature is obtained at each temperature obtained from the temperature sensor from each light source element. While the cooling means is controlled so that the light source element has a desired laser operation set temperature, the temperature of the other light source elements is raised by each electric heater so that the desired laser operation set temperature is obtained.

  According to the first aspect of the present invention, the temperature of the semiconductor laser element array is detected by the temperature sensor, and the operation timing of the semiconductor laser element array is determined by comparing these temperatures with the laser operation set temperature. Is possible.

  According to the invention described in claim 2 of the present invention, in addition to the effect of the invention described in claim 1, it is detected that the semiconductor laser element array is at a temperature higher than the laser operation set temperature and precedes the operation of the semiconductor laser element array. Since the cooling means is driven, it is possible to start safely without causing an abnormally high temperature due to light emission of the semiconductor laser element array.

  According to the third aspect of the present invention, in addition to the effect of the first aspect, the semiconductor laser element array cooling means is provided after the temperature of the semiconductor laser element array below the laser operation set temperature is raised by the electric heater. For example, it is possible to start the apparatus accurately even in a cold region.

  According to the fourth aspect of the present invention, the semiconductor laser device array is operated to emit light when the refrigerator functions, and the semiconductor laser device array is operated by laser even when the temperature fluctuates after light emission. Since it is kept at the set temperature, the reliability can be kept permanently.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a basic configuration of a light source unit according to the present invention, and FIG. 2 shows a perspective view of an assembled state of the light source unit. FIG. 3 is a diagram showing a specific configuration of the present invention, and FIG. 4 shows an example of the cooling means employed in the present invention. FIG. 5 shows a flow of processing of the activation system of the present invention, and FIGS. 6 to 10 show aspects of temperature control by this activation system.

  FIG. 1 is a plan view showing a basic configuration of a light source unit 1 that is a main part of a projection display apparatus P according to the present invention. Three primary colors of laser light are applied to three side surfaces of a synthesis prism 2 arranged in the center. Irradiation surfaces 2R, 2G, and 2B are formed. The irradiation surface 2R is irradiated with red laser light, the irradiation surface 2G is irradiated with green laser light, and the irradiation surface 2B is irradiated with blue laser light.

  In addition to the liquid crystal panels 3R, 3G, and 3B, incident-side polarizing plates 4R, 4G, and 4B and outgoing-side polarizing plates 5R, 5G, and 5B are arranged in parallel to face each irradiation surface 2R, 2G, and 2B. In order to allow a specific linearly polarized light component to enter the liquid crystal panels 3R, 3G, and 3B, the light beams of the respective primary colors are aligned in a predetermined polarization direction (P-polarized light) in the incident-side polarizing plates 4R, 4G, and 4B. After being modulated by the panels 3R, 3G, and 3B, only the S-polarized light component of the modulated light is transmitted from the exit-side polarizing plates 5R, 5G, and 5B.

  Condenser lenses 6R, 6G, and 6B for obtaining a uniform illuminance distribution are arranged in parallel to face the incident side polarizing plates 4R, 4G, and 4B, and further uniformize the luminance of each laser beam. Integrators (fly eye lenses) 7R, 7G, and 7B are arranged in parallel to face the condenser lenses 6R, 6G, and 6B. The integrator 7 </ b> R receives red laser light from the light source element 8, the integrator 7 </ b> G receives green laser light from the light source element 9, and the integrator 7 </ b> B receives blue laser light from the light source element 10.

  The light source elements 8, 9, and 10 are all configured identically, and several tens or more semiconductor laser elements are provided at the tips of heat receiving plates 8a, 9a, and 10a formed of a metal having excellent thermal conductivity. The arrayed semiconductor laser element arrays 8b, 9b, 10b are fixed by, for example, a heat conductive adhesive. For example, the semiconductor laser element array 8b has a red wavelength band around 650 nm, the semiconductor laser element array 9b has a green wavelength band around 550 nm, and the semiconductor laser element array 10b has a blue wavelength band of 440 nm. Near laser light is emitted.

  The primary color laser beams emitted from the thus configured semiconductor laser element arrays 8b, 9b, and 10b must be incident on the combining prism 2 with a predetermined amount of light. Therefore, it is important as a design problem to consider the amount of light emitted from each semiconductor laser element for each primary color, determine the number of elements to be arranged, or set and supply the drive current for each of the three primary colors.

  The light source elements 8, 9, and 10 are configured as described above, and a plurality of light source elements 8, 9, and 10 that emit the same primary color within the irradiation range of the same primary color as shown in FIG. 2G and 2B are arranged in layers. In the figure, the arrangement state of the light source element 10 that emits blue light toward the irradiation surface 2B of the composite prism 2 is illustrated, but the light source element 8 that emits red light and the light source element 9 that emits green light are also irradiated. It arrange | positions similarly toward 2R and 2G. Note that the light source elements 8, 9, and 10 between layers need to be arranged in a zigzag or the like so that the irradiation light is dispersed.

  When the light source unit 1 configured as described above is driven, laser light of three primary colors is emitted from the light source elements 8, 9, 10 toward the irradiation surfaces 2 R, 2 G, 2 B of the synthesis prism 2. The luminance of each color laser beam is made uniform in the integrators 7R, 7G, and 7B, and the illuminance distribution is made uniform in the condenser lenses 6R, 6G, and 6B, and is incident on the incident side polarizing plates 4R, 4G, and 4B.

  The laser beams of the three primary colors made uniform in this way are incident on the liquid crystal panels 3R, 3G, and 3B, and are subjected to gradation (intensity) modulation to form an image. Then, the light enters the combining prism 2. The laser light of the three primary colors subjected to the gradation modulation is combined in the combining prism 2. Then, this projection light exits from the exit surface 2S and is projected onto the screen via the projection lens L.

  When the light source elements 8, 9, 10 are bonded to the heat receiving plates 8 a, 9 a, 10 a with the semiconductor laser element arrays 8 b, 9 b, 10 b by a heat conductive adhesive or screwed, contact at the joint surface Due to the nature of the characteristics, an error occurs in the contact thermal resistance. Further, a difference in thermal resistance due to heat transfer between the joint surfaces and the solid occurs in the path from the heat receiving plates 8a, 9a, and 10a to the outside air (in the case of air cooling) as the final heat radiation destination. These thermal resistance differences cause the temperature of each of the heat receiving plates 8a, 9a, 10a and the semiconductor laser element arrays 8b, 9b, 10b to be non-uniform. If the semiconductor laser element arrays 8b, 9b, and 10b are caused to emit light in this state, the amount of emitted light is not uniform due to the difference in thermal conditions, and the lifetime is also different.

  Therefore, as shown in FIG. 3, the electric heater 20 and the temperature sensor 21 are arranged on all the heat receiving plates 8a, 9a and 10a of the light source elements 8, 9, and 10, and the electric heater 20 and the temperature sensor 21 are connected to the lead wire L1. , L2 is connected to the control device 22. The heat receiving plates 8a, 9a, and 10a are provided in the refrigerant circuits 24R, 24G, and 24B that extend from the refrigerator 23 that serves as a cooling unit and face the irradiation surfaces 2R, 2G, and 2B of the synthetic prism 2 respectively. The heat absorber (evaporator) 25 is fixed by an appropriate means such as a heat conductive adhesive so that heat of the heat receiving plates 8a, 9a and 10a is absorbed by the heat absorber 25.

  FIG. 4 shows an example of the refrigerant circuit in the refrigerator 23. The refrigerant compressor 23a, the condenser 23b, the decompressors 23R, 23G, and 23B, the heat absorber 25, and the accumulator 23c are connected in an annular shape in this order. . The high-temperature and high-pressure gas refrigerant compressed by the refrigerant compressor 23a of this refrigerant circuit is condensed by exchanging heat with the outside air (in the case of air cooling) by the blower fan 23d of the condenser 23b and becomes liquid refrigerant. Next, the refrigerant that has become low temperature and low pressure in the decompressors 23R, 23G, and 23B evaporates in the heat absorber 25. The heat receiving plates 8a, 9a and 10a are cooled by the endothermic action at this time. In addition, by adjusting the throttle amount of the refrigerant in the decompressors 23R, 23G, and 23B, adjusting the air volume of the blower fan 23d, and further adjusting the rotation speed of the refrigerant compressor 23a, the heat absorber 25 for each primary color is adjusted. The cooling capacity can be adjusted.

  Further, signals from the temperature sensors 21 of the light source elements 8, 9, and 10 are inputted, heat generation control of the electric heater 20, refrigerant flow rate adjustment control by the decompressors 23R, 23G, and 23B, and rotation of the refrigerant compressor 23a. A control device 22 is provided to control the heat receiving plates 8a, 9a, and 10a so that the cooling and heating can be mutually controlled so that all the semiconductor laser element arrays 8b, 9b, and 10b are set at the laser operation set temperature. I have to.

  Here, the processing flow of the system according to the present invention will be described with reference to FIG. Before starting the projection display apparatus P, the temperature T of the light source elements 8, 9, and 10 is assimilated to the environmental temperature. For example, when the environmental temperature is 26 ° C., as shown in FIG. The light source elements 8, 9, and 10 are 26 ° C. In the figure, for easy understanding, a blue light source element 10 is illustrated as a representative example, and the temperature state of each light source element 10 can be grasped by a branch number. Further, the temperatures of the light source elements 8, 9, and 10 are individually grasped by the control device 22 that inputs detection signals of the respective temperature sensors 21.

  When the projection display apparatus P of the present invention is activated in such a state (step Sa1), the temperature sensor 21 confirms the state of the temperature T of the light source elements 8, 9, and 10 (step Sa2). A laser operation set temperature Ta (for example, 20 ° C.) preset in the apparatus 22 is compared (step Sa3). If the temperature T is equal to or higher than the laser operation set temperature Ta at this stage, the electric heater 20 for raising the temperature of the light source elements 8, 9, 10 does not operate (step Sa 4), and the refrigerator 23 is driven (heat removal). Operation) is started (step Sa5).

  When the temperature T is lower than the laser operation set temperature Ta, the electric heater 20 for raising the temperature of the light source elements 8, 9, 10 is operated (step Sa9). Note that the laser operation set temperature Ta may be a value obtained by adding an allowable error temperature (for example, 1 to 5 ° C.), and the temperature T may be detected from an arbitrarily determined temperature sensor 21, in which case The temperature detected from the temperature sensor 21 need not be confirmed.

  In this way, when the refrigerator 23 starts driving, the refrigerator 23 is controlled so that the light source elements 8, 9, and 10 have the laser operation set temperature Ta. In this way, the heat absorber 25 is supplied. The heat absorber 25 cools the light source elements 8, 9, and 10 to cool the semiconductor laser element arrays 8 b, 9 b, and 10 b comprehensively. During this time, the temperature sensor 21 confirms the state of the temperature T of the light source elements 8, 9, and 10 (step Sa6) and compares it with the laser operation set temperature Ta (step Sa7).

  When the temperature T and the laser operation set temperature Ta coincide in step Sa7, the semiconductor laser element arrays 8b, 9b, and 10b are powered on and light emission is started (step Sa8). In this way, when the light emission of the semiconductor laser element arrays 8b, 9b, and 10b is started, the temperature state immediately after that includes the difference in thermal resistance as described above. A temperature difference occurs between the elements 10-1 to 10-n.

  When the semiconductor laser element arrays 8b, 9b, and 10b emit light in this state, the temperature of the light source elements 10-1 to 10-n rises almost uniformly as shown in FIG. It will be in the state which remove | deviated from (20 degreeC). Therefore, the control device 22 extracts the maximum temperature value from the plurality of light source elements 8, 9, and 10 connected to the same refrigerant circuit, and this maximum temperature (in the example shown in FIG. 8, in the light source element 10-4). To lower the laser operation set temperature (20 ° C.) to increase the cooling capacity by controlling the refrigerator 23.

  As a result, as shown in FIG. 9, the light source element 10-4 can be made to coincide with the laser operation set temperature of 20 ° C., but the temperature of the other light source elements also drops uniformly, so that the laser operation set temperature of 20 ° C. A temperature drop from 1 ° C. to 1 ° C. to 4 ° C. will occur. Therefore, the control device 22 compares the temperature value detected by the temperature sensor 21 of each light source element 8, 9, 10 with the laser operation set temperature (20 ° C.), and the temperature of the corresponding light source element is the laser operation set temperature (20 Current is passed through the electric heater 20 so that the temperature of the light source element is raised.

  That is, in FIG. 9, for example, the light source element 10-1 is 4 ° C. lower than the laser operation set temperature (20 ° C.), so the control device 22 raises the temperature by 4 ° C. by the electric heater 20 and the light source element 10-2. Will be raised by 1 ° C. In this way, the temperatures of the light source elements other than the light source element 10-4 are complemented, and all the light source elements 10-1 to 10-n are set to the target laser operation set temperature (20 ° C.) as shown in FIG. be able to.

  In this way, when cooling light source elements connected to the same refrigerant pipe, the maximum temperature value indicated by a specific light source element is lowered to the target laser operation set temperature by a refrigerator, and other light source elements are electrically heated. The temperature is raised by the heater, and the temperature T of the light source element and the laser operation set temperature Ta are always collated. Therefore, even when the temperature changes due to light emission of the semiconductor laser element array at the start of the apparatus, it is accurate. Temperature control is possible.

  Since the present invention is configured in this way, the light source element is cooled in advance when the apparatus is started, and then the semiconductor laser element array emits light. Therefore, the temperature due to the heat generated by the light emission of the semiconductor laser element array. While suppressing the rapid increase, the temperature control and the time until the apparatus operates normally can be shortened, and the semiconductor laser element array can be protected at the same time.

  In the above-described embodiment, an example in which a transmissive liquid crystal panel is used has been described. However, as an alternative display element, for example, when a light source unit is configured in a three-plate type or a single plate type using a reflective liquid crystal panel. Can achieve the same effect. The present invention can also be employed in DLP (Digital Light Processing).

It is a top view which shows the basic composition of the light source unit of this invention. It is a perspective view which shows the assembly state of the light source unit of this invention. It is a figure which shows the system configuration | structure of this invention. It is a figure which shows the example of the cooling means employ | adopted as this invention. It is a figure explaining the processing flow of the system in this invention. It is a figure explaining the aspect of cooling of the light source element in this invention. It is a figure explaining the aspect of cooling of the light source element in this invention. It is a figure explaining the aspect of cooling of the light source element in this invention. It is a figure explaining the aspect of cooling of the light source element in this invention. It is a figure explaining the aspect of cooling of the light source element in this invention.

Explanation of symbols

P ... Projection type image display device L ... Projection lens 1 ... Light source unit 2 ... Synthetic prism 3R, 3G, 3B ... Liquid crystal panel 4R, 4G 4B: Incident side polarizing plate 5R, 5G, 5B: Output side polarizing plate 6R, 6G, 6B: Condenser lens 7R, 7G, 7B: Integrator 8, 9, 10... Light source element 8a, 9a, 10a... Heat receiving plate 8b, 9b, 10b... Semiconductor laser element array 20. Temperature sensor 22 ... Control device 23 ... Refrigerator 24R, 24G, 24B ... Refrigerant circuit 25 ... Heat absorber

Claims (4)

A projection-type image display device in which projection light is obtained by modulating and synthesizing laser beams of three primary colors according to image information;
A semiconductor laser element array in which a plurality of semiconductor laser elements are arranged on the same substrate is arranged on a heat receiving plate, and an electric heater and a temperature detecting means (temperature sensor) of the semiconductor laser element array are arranged on the heat receiving plate. A plurality of light source elements are arranged in a hierarchy so as to be guided to the irradiation surface of the synthesis prism for each of the three primary colors to constitute a light source unit,
The light source element is connected to the cooling means, and the electric heater and the temperature sensor are connected to the control means,
An operation timing of the semiconductor laser element array is determined by comparing the temperature of the temperature sensor with a preset laser operation set temperature by the control means. Boot system.   When the temperature detected by the temperature sensor is equal to or higher than the laser operation set temperature, the cooling means is immediately driven to lower the temperature of the semiconductor laser element array, and then the semiconductor laser is detected when the temperature sensor detects the laser operation set temperature. 2. The start-up system for a projection display apparatus according to claim 1, wherein the element array is operated.   When the temperature detected by the temperature sensor is equal to or lower than the laser operation set temperature, the semiconductor laser element array is immediately heated by the electric heater, while the temperature detected by the temperature sensor exceeds the laser operation set temperature. 2. The projection type image display apparatus according to claim 1, wherein the cooling means is driven at the time of the operation, and the semiconductor laser element array is operated when the temperature of the semiconductor laser element array is lowered to a laser operation set temperature. . A projection-type image display device in which projection light is obtained by modulating and synthesizing laser beams of three primary colors according to image information;
A semiconductor laser element array in which a plurality of semiconductor laser elements are arranged on the same substrate is arranged on a heat receiving plate, and an electric heater and a temperature detecting means (temperature sensor) of the semiconductor laser element array are arranged on the heat receiving plate. A plurality of light source elements are arranged in a hierarchy so as to be guided to the irradiation surface of the synthesis prism for each of the three primary colors to constitute a light source unit,
The light source element is connected to the cooling means, and the electric heater and the temperature sensor are connected to the control means,
When the temperature detected by the temperature sensor is equal to or higher than the laser operation set temperature, the cooling means is immediately driven to lower the temperature of the semiconductor laser element array, and then the semiconductor laser is detected when the temperature sensor detects the laser operation set temperature. To activate the element array,
After the semiconductor laser element array is operated, the cooling means is controlled so that the light source element showing the highest temperature value among the temperature values obtained from the temperature sensors from the respective light source elements has a desired laser operation set temperature. A startup system for a projection display apparatus, wherein the temperature of the other light source elements is raised by the respective electric heaters to achieve a desired laser operation set temperature.

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