JP3988083B2 - Light source device, projector, and projection television - Google Patents

Description

  The present invention includes a light source body including a light emitting body including a light emitting layer composed of an organic EL (electroluminescence) element and a cooling unit, and guides light emitted from the light emitting body to a liquid crystal panel and displays the light on the liquid crystal panel. The present invention relates to a projection display device that magnifies and projects an image with a lens.

  The present invention also relates to a cooling control technique for cooling a light emitting body using a light emitting layer composed of an organic EL (electroluminescence) element used in various fields.

  More specifically, a light source device in which a temperature detection unit and an elapsed time measurement unit are added to a light source body including a light emitter and a cooling unit, and the cooling unit is controlled by the temperature detection unit and the elapsed time measurement unit in the light source device. The present invention relates to a method and apparatus for controlling a light source device.

  2. Description of the Related Art In recent years, various electronic display devices have been developed or commercialized in addition to cathode ray tube type displays due to the rapid development of semiconductor technology. As one of them, a projection display device is in the spotlight as an advantageous technique in terms of low power consumption and light weight.

  As one type of the projection display device, there is known a liquid crystal projector that enlarges and projects an image of a liquid crystal panel with a projection lens and displays the image on a reflective or transmissive screen. An example of this liquid crystal projector is shown in FIG.

  The liquid crystal projector shown in the figure includes a light source lamp unit 202 in a housing 201. As the light source lamp unit 202, a discharge lamp such as a metal halide lamp or a halogen lamp is used. The light emitted from the light source lamp unit 202 is guided to the dichroic mirrors 204 and 205 via the mirror 203, and is divided into red light, green light, and blue light. Of the three component light components, the red light passes through the mirror 206 to the red display liquid crystal panel 209, the green light directly into the green display liquid crystal panel 210, and the blue light passes through the mirrors 207 and 208. To the blue display liquid crystal panel 211.

 In each of the three liquid crystal panels 209 to 211, an image displayed on the liquid crystal panel is illuminated with light of each color, and the light is combined by the dichroic prism 212. The synthesized light is magnified by the projection lens 213, and is magnified and projected on, for example, a reflective screen (not shown).

  However, in a liquid crystal projector using such a light source lamp unit 202, it is necessary to irradiate the liquid crystal panel with light emitted from a metal halide lamp or a halogen lamp with good parallelism. For this purpose, as shown in FIG. 31 described above, it is necessary to provide the light source lamp unit 202 with a reflector 202A having a considerably large opening, and there is a serious problem that it is difficult to meet the demand for weight reduction and downsizing of the entire projector.

  Further, as shown in FIG. 31, it is desirable to cool the lamp of the light source. In particular, as the lamp capacity increases, a cooling fan having a high cold air capacity is required. The installation of a cooling fan that performs this forced air cooling is also a factor that hinders lighter and smaller projectors.

  In addition, as described above, in the case of a so-called three-plate type liquid crystal projector in which three individual liquid crystal panels are provided for red, green, and blue, the light emitted from one lamp light source is three sheets. A branching optical system that divides and irradiates the liquid crystal panel for each color is required. Therefore, the above-described weight reduction and downsizing become increasingly difficult.

[First prior art]
In order to overcome such a situation, in recent years, those using organic EL elements as light emitters have been proposed. It has been reported many that EL elements using an organic thin film as a light emitting layer emit light with high luminance. This luminous body is a thin planar light source on which an electroluminescent (electroluminescence: EL) layer made of an organic thin film is formed. Organic EL elements can be driven at a lower voltage and have higher brightness than inorganic EL elements. Therefore, organic EL elements are said to be suitable for enlarged projection type projection display devices, and are actively studied for practical use. It is in place.

  An example of a three-plate liquid crystal projector using this organic EL element as a light source is shown in FIGS. In the liquid crystal projectors shown in these figures, organic EL elements that emit red, green, and blue light are used in the vicinity of the back sides of the three liquid crystal panels 221, 222, and 223 that display red, green, and blue, respectively. The light source bodies 224, 225, and 226 are arranged separately. Reference numeral 227 denotes a dichroic prism, and 228 denotes a projection lens. An example of this type of projection display device is disclosed in Japanese Patent Laid-Open No. 51-119243 (Patent Document 1).

  Even in a three-plate liquid crystal projector using such an organic EL element as a light source body, the organic EL element generates heat as it is driven, and thus needs to be cooled.

[Second prior art]
As a means for forcibly cooling such an organic EL element, it is conceivable to use an electric cooling element utilizing the Peltier effect.
JP 51-119243 A

  However, in the liquid crystal projector of the first prior art shown in FIGS. 32 and 33 described above, although a reduction in size and weight is promoted by adopting a planar light emitting body using an organic EL element, it remains unsolved. These problems remain as follows, and these problems have become obstacles and have not yet been put into practical use.

  First, even though it is an organic EL element, heat is generated with its driving, and there is a problem that the light emission performance is gradually deteriorated due to this heat generation and the life as a light source is shortened.

  In addition, if the light emission performance of the light source body using the organic EL element has fallen to an allowable limit, it is desired to replace only the light source body. In particular, in a color display three-plate liquid crystal projector, a light source body is installed for each of the three liquid crystal projectors, and the number thereof is large. Since the performance deterioration of one or two light source bodies breaks the balance of colors displayed on the screen, the influence is great. In such a case, it is economical if only the light source that has reached the end of its life can be easily replaced. However, conventionally, a structure that can be easily replaced independently for each light source is not proposed. For this reason, the repairer exchanged the light source body while taking a lot of time and effort from the substrate on which the light source body was mounted, and there was no means.

  Particularly important at the time of the replacement is not only ensuring the electrical connection with the light source body after the replacement but also returning it to its optical predetermined position. This is because if the direction and position of the replaced light source body are deviated, the incident state of light on the liquid crystal panel changes, and part of the image on the screen becomes dark, which may deteriorate the display performance.

  Another important thing at the time of replacement is proper judgment of the replacement time. If the replacement is delayed, it may be necessary to accept a screen with low brightness or an unbalanced color balance. On the other hand, if the replacement is too early, there is a problem in terms of economy. In other words, it is important to appropriately determine the replacement time, but no effective proposal has been made in the past.

  Further, the light emitted from the planar light source body using the organic EL element is not necessarily parallel light, and enters the liquid crystal panel with a wide spread directivity. For this reason, there is a lot of useless light which is not involved in the display of the image of the liquid crystal panel in the light emitted from the light source body, and accordingly, the luminance of the display screen is lowered. In addition, if the display luminance is increased by taking this waste amount into consideration, the light emission power of the organic EL element will be forcibly increased, and this will not improve the light emission performance due to heat generation. It causes a vicious circle that results in further shortening.

  In terms of improving the light output efficiency from the light source body, the transparent glass substrate disposed on the light output side of the organic thin film as the organic EL element also plays an important role. It was plate-shaped.

  In the first prior art, a practical projection display device is difficult due to various problems as described above.

  Further, in the second prior art, when a light emitter provided with an organic EL element and a cooling means are used and an electronic cooling element is used to cool the organic EL element, the organic EL element is turned on and cooled at the same time. When the driving of the element is started, there is a problem that the temperature of the organic EL element rises before the organic EL element is cooled, and the organic EL element is thermally deteriorated.

  Moreover, when starting a cooling element first and lighting an organic EL element after that, there exists a problem that an organic EL element cools too much before an organic EL element light-emits, and a dew condensation arises.

    Furthermore, even when the use of the light source device is terminated, there is a problem in that the organic EL element is thermally deteriorated or condensed if the timing of turning off the organic EL element and stopping the cooling element are poor.

  The main object of the present invention is to provide a projection display apparatus that employs a light source body composed of a light emitting body including an organic EL element and a cooling means that overcomes such difficulties and is light, small, and practical. The first purpose.

  In particular, the present invention suppresses a decrease in light emission performance due to heat generation of the organic EL element, extends the lifetime, stabilizes the luminance, and always ensures the maximum luminance. Objective.

  In addition, the present invention makes it possible to easily replace the light source body by the organic EL element for each light source body, in a state where the electrical connection and the optical position are secured, and to make the replacement work more efficient and facilitate the maintenance inspection. The other specific purpose is to achieve this.

  Furthermore, another specific object of the present invention is to make it possible to easily determine the timing of the replacement time, to ensure a high quality screen display, and to facilitate maintenance and inspection.

  Still another object of the present invention is to improve the efficiency of light incident on the liquid crystal panel.

  Still another object of the present invention is to improve and improve the light output efficiency from the light source body by the organic EL element with respect to the transparent substrate of the light source body.

  In addition, the present invention has another main second object to provide a light source device capable of preventing thermal degradation of the organic EL element and preventing the occurrence of condensation, and a control method and device for the light source device. It is said.

  Therefore, the light source device according to the present invention includes a first light emitter that emits first light, a second light emitter that emits second light different from the first light, and the first light emission. A first electronic cooling element that cools the body, a second electronic cooling element that cools the second light emitter, a first lighting switch that controls the supply of power to the first light emitter, A first cooling switch for controlling power supply to the first electronic cooling element; a second lighting switch for controlling power supply to the second light emitter; and the second electronic cooling element And a second cooling switch for controlling the supply of electric power to the apparatus. This may include a first light emitter that emits first light and a first electronic cooling element that cools the first light emitter. In any case, heat generated in the light emitter can be cooled, and deterioration of the light emitter can be suppressed.

A first lighting switch for controlling the supply of electric power to the first light emitter;
And a first cooling switch that controls supply of electric power to the first electronic cooling element.

  The control of the first lighting switch for the light source device to start supplying power to the first light emitter is the first for starting supplying power to the first electronic cooling element. It is preferably performed after the control of one cooling switch.

  The light source device controls the first lighting switch for stopping the supply of power to the first light emitter, and the first light switch for stopping the supply of power to the first electronic cooling element. It is preferably performed after the control of one cooling switch.

  It is preferable that the light source device includes a first temperature switch that drives and controls the first lighting switch and the first electronic cooling element.

  In the light source device, it is preferable that a first heat sink is disposed between the first light emitter and the first electronic cooling element.

  In the light source device, it is preferable that grease having high thermal conductivity is disposed between the first light emitter and the first heat sink.

  In the light source device, it is preferable that a sheet having high thermal conductivity is disposed between the first light emitter and the first heat sink, and the first light emitter is removable.

  In the light source device, it is preferable that the first heat sink includes a temperature sensor.

  The light source device has a light emitting film structure in which the first light emitter includes a first electrode, a second electrode, and a light emitting layer positioned between the first electrode and the second electrode. It is preferable to contain.

  A display according to the present invention includes the light source device.

  A projector according to the present invention includes the light source device.

  A projection television according to the present invention includes the light source device.

  Hereinafter, a projection display device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following embodiments, a liquid crystal projector is employed as the liquid crystal display device.

(First embodiment)
A first embodiment will be described with reference to FIGS. The liquid crystal projector shown in FIG. 1 is formed as a rear projection type three-panel liquid crystal projector.

  This liquid crystal projector has a housing 11, and corresponds to each of the three liquid crystal panels 12R, 12G, and 12B that display red, green, and blue images in the housing 11 and the liquid crystal panels. Plate-like light emitters 13R, 13G, and 13B, plate-like cooling bodies 14R, 14G, and 14B as cooling means installed in the respective light source bodies, a dichroic prism 15, and a projection lens 16. . The light emitters 13R, 13G, and 13B and the cooling bodies 14R, 14G, and 14B constitute a light source body. The liquid crystal panels 12R to 12B and the light source bodies (light emitting bodies 13R to 13B, cooling bodies 14R to 14B) are arranged on the light incident side of each side surface of the dichroic prism 15 for each set of display colors.

  A projection lens 16 is disposed on the light output side of the dichroic prism 15. A transmissive screen 17 is arranged at a predetermined distance on the light output side of the projection lens 16. Although the projection lens 16 is represented by a single lens in the figure, it is usually composed of a plurality of lenses.

  This liquid crystal projector belongs to the rear projection type, that is, an enlarged image is projected from the rear side (the side where the projector exists) of the transmission type screen 17 having a size of about 20 inches. Of the type. In the liquid crystal projection television, this screen is fixed to the housing 11.

  Here, the side surface on the light source side of each of the liquid crystal panels 12R to 12B is referred to as a back surface and the direction thereof is referred to as a back surface side, and the light output side of each of the liquid crystal panels 12R to 12B is referred to as a front surface side as necessary. Each of the liquid crystal panels 12R, 12G, and 12B is formed by laminating a substrate on which an element for electrically driving the sandwiched liquid crystal layer, a polarizing plate, a retardation plate, and the like, and displays red, green, and blue images. It is supposed to be displayed. Each liquid crystal panel has a diagonal size of, for example, 33 mm (1.3 inches).

  Each of the light emitters 13R, 13G, and 13B uses an organic EL (electroluminescence) element in which a structure of an electroluminescent layer made of an organic thin film that emits red, green, or blue light is formed in a plate shape.

  That is, each of the light emitting film portions of the light emitters 13R, 13G, and 13B has a transparent electrode layer comprising a glass substrate as a transparent substrate 20 and a transparent conductive thin film layer formed on the glass substrate, as shown in FIG. 21, a light emitting layer 22 formed on the electrode layer and formed of an organic thin film layer that emits red, green, or blue light, and a reflection formed of a metal film that also serves as a reflection mirror laminated with the light emitting layer interposed therebetween. And an electrode layer 23. The transparent electrode layer 21, the light emitting layer 22, and the reflective electrode layer 23 form a light emitting film structure LT. The effective light emitting area of the light source body is formed with a diagonal size of 33 mm or more, and is arranged close to the back side of the liquid crystal panel.

  The light emitting layer 22 emits red, green, or blue light by an electric field applied between the transparent electrode layer 21 and the reflective electrode layer 23. The organic material for forming the organic thin film is, in the case of red, a material obtained by adding a red fluorescent dye to a quinolinol aluminum complex (wavelength of about 610 nm), in the case of green, for example, a quinolinol aluminum complex (wavelength of about 540 nm), blue In this case, an oxazole complex of zinc or the like (wavelength of about 460 nm) is used.

  As shown in FIG. 3, each of the light emitters 13R, 13G, and 13B includes a sealing substrate 24 that is attached to the back side of the light emitting film structure LT and seals the light emitting film structure LT. As a material of the sealing substrate 24, metals such as aluminum and copper are suitable.

  Each of the cooling bodies 14R, 14G, and 14B includes a heat conductor 25 that transmits conduction heat from the sealing substrate 24, and a plate-like electronic cooling element 26 that is attached to the back side of the heat conductor 25. Is provided. For the heat conductor 25, a liquid or metal that is a good heat conductor is used. For example, silicone grease having excellent thermal conductivity, or an adhesive having excellent thermal conductivity. In addition, solder may be used. The heat conductor preferably has heat resistance that can withstand 100 to 200 ° C.

  The electronic cooling element 26 is an element utilizing the Peltier effect that absorbs heat and generates heat when an electric current is passed through, and the heat absorption side is integrally attached to the heat conductor 25 side.

  For this reason, the heat generation of the light emitting film structure LT transmitted to the heat conductor 25 is absorbed by the electronic cooling element 26, and the heat is radiated from the opposite side. Although the heat radiation side of the electronic cooling element 26 may be natural heat radiation, it is desirable to actively dissipate heat by attaching a heat sink material (not shown). For example, a radiation fin is preferable.

  More preferably, for the purpose of positively radiating heat from the heat radiating fins, an air cooling fan (for example, a small fan) for the heat radiating fins is provided on the back surface of the heat radiating fins. The heat dissipating fan may be provided for each heat dissipating fin, or may be provided on a part of the housing for the purpose of convection of air in the housing.

  The effect of this embodiment is demonstrated. Light emitted from the red, green, and blue light emitters 13R, 13G, and 13B is incident on the liquid crystal panels 12R, 12G, and 12B facing each color. This incident light illuminates the liquid crystal panels 12R, 12G, and 12B displaying red, green, and blue images. The image display light emitted from the liquid crystal panels 12R, 12G, and 12B is incident on the dichroic prism 15 and combined, and the combined light is magnified, for example, 10 times by the projection lens 16. The enlarged light is projected onto the transmission screen 17. As a result, a color image having a diagonal size of, for example, 330 mm (13 inches) is displayed on the screen 17.

  During this display, heat generated from the light emitting film structures LT of the light emitters 13R, 13G, and 13B is transmitted to the cooling body 26 via the sealing substrate 24 and the heat conductor 25. The cooling body 26 absorbs and generates heat and dissipates it. For this reason, most of the heat generated in the light emitting film structure LT, that is, the light emitting layer 22, is not accumulated in the light emitters 13R, 13G, and 13B, but is dissipated to the outside and actively cooled.

  Therefore, deterioration of the light emitting performance of the light emitting layer 22 due to heat generation is suppressed, and the lifetime of the light source is prolonged. In addition, the brightness of the display screen is maintained at a high value, and a stable bright screen is created.

  Furthermore, a light-emitting body using an organic EL element is mounted together with the cooling body, and the advantages of weight reduction and downsizing of using the organic EL element as a light source are enjoyed, and the conventional difficulties are overcome and put into practical use. A possible projection display device can be provided.

  Note that the light emitters are not limited to those emitting only a specific color of red, green, or blue as described above, and the composition of red, green, and blue colors is common to the three light emitters. You may mount the light emitting layer which emits light, or the light emitting layer which emits white light containing those three primary colors. In this case, in the configuration of FIG. 1, wavelength filters that transmit only red, green, and blue colors may be inserted between the liquid crystal panels 12R, 12G, and 12B and the dichroic prism 15, respectively.

  It is also possible to combine one liquid crystal panel in which red, green, and blue color filters for each pixel are formed, one light emitter having an organic EL element structure that generates white light, and a projection lens.

  Furthermore, as a screen, a projector structure using a reflective screen having a size of about 100 inches can be used instead of the transmissive type. When a reflection type screen is used, the image projected on the screen is observed from the side where the projector is present.

(Second Embodiment)
A second embodiment will be described with reference to FIGS. This embodiment also relates to cooling of a light emitter using an organic EL element, as described above. Note that the same or equivalent components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified (this description is made in the third embodiment and that. The same applies to the following embodiments).

  The liquid crystal projector shown in FIG. 4 is formed as a rear projection type three-panel liquid crystal projector. Unlike the liquid crystal projector of the first embodiment, the cooling means for the light emitters 13R, 13G, and 13B using organic EL elements is different. Although the thing of the 1st embodiment used the electronic cooling element, in this embodiment, it is set as the cooling body using the radiation fin.

  As shown in FIG. 4, cooling bodies 31R, 31G, and 31B as cooling means for natural heat dissipation are attached to the back surfaces of the light emitters 13R, 13G, and 13B, respectively. Each of the cooling bodies 31R, 31G, and 31B includes a heat conductor 25 formed on the sealing substrate 24 and heat radiation fins 32 bonded to the heat conductor 25, as shown in FIG.

  The heat radiating fins 32 are made of, for example, an aluminum material as a good heat conductor. Moreover, the surface of the radiating fin 32 opposite to the heat conductor 25, that is, the radiating surface, has a vertical undulation composed of a plurality of irregularities so that the cross section of the radiating surface is corrugated (vertical direction of the radiating fin 32 in FIG. 5). Is formed. It is more preferable to provide a heat radiating fan similar to that described in the first embodiment on the back surface of the heat radiating fin or a part of the housing 11.

  For this reason, the heat generated from the light emitting film structure LT is guided to the heat radiation fins 32 through the sealing substrate 24 and the heat conductor 25, and is dissipated from the heat radiation surface by natural heat radiation. As a result, also in the second embodiment, cooling is performed to satisfactorily suppress the accumulation of heat generated by the light emitters 13R, 13G, and 13B, and excellent effects equivalent to those in the first embodiment can be obtained. Further, in this case, since the cooling means is a heat radiating fin, there is an advantage that the power supply circuit can be miniaturized because there is no need to energize unlike the electronic cooling element.

  The cooling bodies 31R, 31G, and 31B according to the second embodiment described above can be variously modified as shown in FIGS. The cooling body shown in FIG. 6 is obtained by integrally forming the above-described heat radiation fin, heat conductor, and sealing substrate to form a sealing substrate 33 with heat radiation fins. Thereby, a more compact configuration is possible.

  Further, the cooling body shown in FIG. 7 is formed by integrally forming the heat sink, heat conductor, and sealing substrate in the same manner as in FIG. The central portion CT of the heat radiating surface of the heat radiating fin is raised outside the other portions while maintaining the corrugated shape, and the surface area is increased. This is because the degree of heat generation is known to be higher at the center of the surface of the planar light emitting layer made of an organic EL element, so that the cooling of this part is promoted more strongly.

(Third embodiment)
A third embodiment will be described with reference to FIGS. This embodiment relates to a light emitter exchange structure using an organic EL element.

  The liquid crystal projector shown in FIG. 8 is formed as a rear projection type three-panel liquid crystal projector. On the back side of each of the three liquid crystal panels 12R, 12G, and 12B, a light emitter 13R (13G, 13B) that can be detachably attached and a cooling unit that is integrally attached to the back side of the light emitter 13R. A body 34R (34G, 34B). The cooling body 34R (34G, 34B) is configured in the same manner as in FIG. 6 described above, but the size of the pasting area is slightly smaller than the area on the back side of the light emitting body 13R (13G, 13B). .

  As shown in FIGS. 8, 10, and 11, a board 35 is attached to the periphery of the remaining end portion on the back side of the light emitter 13 </ b> R (13 </ b> G, 13 </ b> B). As will be described later, the board 35 functions as a guided member at the time of replacement / attachment, and has a function of establishing electrical continuity with the power supply circuit via its lower end.

  The liquid crystal projector further includes a pair of concave guides 36, 36 which are arranged to face each other on a base (not shown) for guiding the board 35, that is, the set of the light emitter and the cooling body in the vertical direction. Have The positions of the guides 36, 36 on the base are such that the light emitter 13R (13G, 13B) is accurately positioned in the vicinity of the back surface of the liquid crystal panel 12R (12G, 12B) when the board is inserted. It is positioned so that the optical axis to reach the set position straight and accurately.

  As shown in FIG. 9, a connector 37 is disposed at a position on the base between the pair of guides 36 and 36. A protrusion-like insertion portion 35L (see FIGS. 10 and 11) integrally formed at the lower end portion of the board 35 is inserted into the connector 37 so as to freely advance and retract. On one surface of the insertion portion 35L, a terminal portion TN is mounted which is a printed circuit for power and signal transmission leading to the light emitter 13R (13G, 13B). For this reason, when the base 35 (that is, a set of the light emitter and the cooling body) is inserted into the connector 37 while being guided by the guides 36, 36, the power / signal circuit (not shown) and the light emitter 13R (13G, 13B) are electrically connected. Will be conducted. Other configurations and functions are the same as those of the above-described embodiment.

  For this reason, the light emitting performance of the light emitters 13R, 13G, and 13B is reduced to an allowable limit, and any light emitter can be freely replaced at any time when it is determined that the lifetime has expired or during maintenance and inspection. . At the time of replacement, only the old light emitter can be pulled out together with the board 35, and the new light emitter can be smoothly inserted using the guide function of the board 35 and the guides 36, 36. As a result, each light emitter can be easily replaced, reducing labor for maintenance and inspection, and since only an arbitrary light emitter can be replaced independently, it contributes to reduction of maintenance inspection costs and maintenance parts costs. .

  In particular, in a three-panel type liquid crystal projector for color display, a light emitter is installed for each of the three liquid crystal projectors, and the number of the light emitters is large. However, since it can be easily replaced, it is not possible to drive while maintaining the balance of display colors. The state of stable and low display quality can be reduced or avoided.

  In addition to ensuring the electrical connection with the light emitting body after replacement, the light emitting body can be easily and accurately returned to a predetermined optical position after replacement by the accurate guide function of the guides 36 and 36. Since the direction and position of the replaced illuminant do not deviate from those before the replacement, the incident state of light on the liquid crystal panel is unchanged, and the display performance can be stabilized with high quality.

  The board as the guided member, the shape as the guiding member, and the guiding mechanism can be variously modified within the scope of the present invention.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. This embodiment relates to an improvement in the direction of light emitted from a light emitter using an organic EL element.

  The liquid crystal projector according to the present embodiment employs the optical arrangement shown in FIGS. This optical arrangement may be adopted for a three-plate liquid crystal projector as described above, or may be adopted for a single-plate liquid crystal projector.

  According to the optical arrangement shown in FIGS. 12 and 13, the lens array 41 as directivity adjusting means is provided between the liquid crystal panel 12R (12G, 12B) and the light emitter 13R (13G, 13B) using an organic EL element. Is inserted. A plurality of microlenses 41a,..., 41a are two-dimensionally formed on the light incident side of the lens array 41, that is, the incident surface on the light emitter side. The pitch of the plurality of microlenses 41a,..., 41a is formed at a ratio of about 4.5: 1 with respect to the pixel pitch of the liquid crystal panel 12R (12G, 12B), for example, and moire does not occur or is conspicuous. There is no optimization as much as possible.

  Expressing this quantitatively, when the focal length of the microlens is approximately 1 mm substantially matching the light emitting layer of the light emitter and the pixel size of the liquid crystal panel is P (for example, P = 33 μm), the radius of curvature of the microlens 41a Is preferably about 500 μm and the lens pitch is 4.5 P (for example, 150 μm).

  For this reason, the light emitted from the light emitter 13R (13G, 13B) as the surface light source usually includes a light component in a considerably random direction, but each component of this light is a microlens 41a, .., 41a, and the directivity is adjusted. Preferably, most of the light is aligned with substantially parallel light and enters the liquid crystal panel 12R (12G, 12B).

  Therefore, most of the light emitted from the light emitter 13R (13G, 13B) is incident on the liquid crystal panel 12R (12G, 12B) efficiently and with little waste. This prevents a decrease in the brightness of the display screen. In other words, the luminous intensity of the organic EL element can be reduced by the amount of light that is incident on the liquid crystal panel efficiently with the light directivity in parallel. It is also possible to prevent the shortening.

  Further, among the light emitted from the light emitter 13R (13G, 13B) or the light incident on the lens array 41, the light component totally reflected on the light incident side or light emitting side surface of the lens array 41 (in FIG. 12). (See arrow A in FIG. 4) is somewhat present due to the contribution of the microlenses 41a,.

  When the light component totally reflected in this way returns to the light emitter 13R (13G, 13B), the light component is reflected by the reflective electrode layer of the light emitter and recycled to the incident light to the lens array 41 again. . For this reason, the arrangement of the lens array 41 also contributes to an improvement in utilization efficiency of light emitted from the light emitter.

  A modification of the fourth embodiment is shown in FIGS. In the optical arrangement according to this modification, a prism array 42 as directivity adjusting means is inserted as shown in the drawing instead of the lens array. The prism array 42 is formed by two-dimensionally forming a plurality of microprisms 42a,. Like the lens array, the plurality of microprisms 42a,..., 42a are such that the total reflection of incident light by the boundary surface is as small as possible and parallel light is emitted toward the liquid crystal panel as much as possible. It is desirable to set the size, height to the apex, pitch, etc. As a result, it is possible to obtain the same effects as those of the lens array described above.

(Fifth embodiment)
A fifth embodiment will be described with reference to FIGS. This embodiment relates to improving the efficiency of light emitted from a light emitter using an organic EL element.

  The liquid crystal projector according to the present embodiment employs a light emitter shown in FIG. This light emitter may be employed in a three-plate liquid crystal projector or a single-plate liquid crystal projector.

  According to the light emitter shown in FIG. 16, a glass substrate 43 as a transparent substrate and a light emitting film structure LT (the transparent electrode layer 21, the light emitting layer 22, and the reflective electrode layer 23) laminated on the glass substrate 43 are provided. Prepare. Among these, a lens array structure in which a plurality of dome-shaped lenses 43a,..., 43a are two-dimensionally arranged is formed on the exit surface of the glass substrate 43 on the light exit side. The pitch of the plurality of lens arrays is as fine as possible and is optimized so that the emitted light is emitted as much as possible without being totally reflected (see arrow A in the figure). Expressing this quantitatively, in the lens array structure, when the thickness of the glass substrate 43 is 1 mm and the pixel pitch of the liquid crystal panel is P (for example, P = 33 μm), the radius of curvature of the lens 43 is 330 μm, and the lens pitch is 4 A curvature and a lens pitch of about 5P (for example, 150 μm) are preferable.

  For this reason, since the lens array structure is present, the light emitted as a surface light source in the entire light emitting layer 22 (for the sake of clarity, only a part of the light emission is shown) is shown in FIG. Compared with the case of the glass substrate 20 having such a flat light emitting surface, the total reflection of the entire surface is reduced. That is, the light output efficiency toward the liquid crystal panel 12R (12G, 12B) is remarkably increased by the lens array structure. For this reason, waste of the emitted light is reduced, a bright screen screen with high luminance can be obtained, and display quality can be improved.

  In FIG. 16, it is assumed that one large dome-shaped lens is formed on the light emitting surface of the glass substrate 43 as a whole. In such a case, the substrate becomes considerably thick at the center of the substrate surface. The lens array structure described above is more suitable for the present invention because the total reflection is not lost so much.

  FIG. 18 shows a modification of the fifth embodiment. In this modification, a microprism array 43b is used instead of the microlens array 43a. The light emitting body of this modification also includes a glass substrate 43 as a transparent substrate and a light emitting film structure LT (the transparent electrode layer 21, the light emitting layer 22, and the reflective electrode layer 23) laminated on the glass substrate 43.

  Among these, a prism array structure in which a plurality of triangular prisms 43b,..., 43b are two-dimensionally arranged is formed on the light exit surface of the glass substrate 43 on the light exit side. The pitch of the plurality of prism arrays is as fine as possible and is optimized so that the emitted light is emitted as much as possible without being totally reflected (see arrow A in the figure). Therefore, the fifth modification shown in FIG. 18 also improves the emission efficiency as in the structure shown in FIG.

(Sixth embodiment)
A sixth embodiment will be described with reference to FIGS. This embodiment relates to a projection display device including a light emitter using an organic EL element and having a resonator structure, and thereby relates to improvement of directivity and spectrum waveform of the light emitter itself.

  In the liquid crystal projector according to the present embodiment, as shown in FIG. 19, light emitters 13R (13G, 13B) are separately arranged on the back side of the liquid crystal panel 12R (12G, 12B). Each of the light emitters 13R, 13G, and 13B has a resonator structure that has been actively developed in recent years, unlike the above-described ones. As this resonator structure, for example, the one disclosed in Technical Research Report OME94-79 of the Institute of Electronics, Information and Communication Engineers is known.

Specifically, each of the light emitters 13R, 13G, and 13B includes a transparent substrate 50 such as glass, a half mirror layer 51 made of a dielectric multilayer film, and a transparent dielectric film such as SiO ₂ as shown in FIG. Spacer layer 52, transparent electrode layer 53 made of a transparent conductive film such as ITO (indium tin oxide), hole injection layer 54 made of an organic thin film that contributes to electroluminescence, light emitting layer 55 made of an organic thin film that emits light, and metal film The reflective electrode layers 56 made of are laminated in this order. Among these, the half mirror layer 51, the spacer layer 52, the transparent electrode layer 53, the hole injection layer 54, the light emitting layer 55, and the reflective electrode layer 56 form a light emitting film structure LT.

  Since the half mirror layer 51 and the reflective electrode layer 56 constitute a resonator, the length of the resonator (that is, the optical path between the half mirror layer 51 and the reflective electrode layer 56) among the light emitted from the light emitting layer 55. Only light having a wavelength determined by a certain interval) resonates and is efficiently emitted to the outside. This emitted light becomes light for illuminating the liquid crystal panels 12R, 12G, and 12B, and most of the other wavelength components are not emitted to the outside.

  The resonator length that determines the emission wavelength at the spectrum center can be changed by adjusting the thickness of the spacer layer 52 and the transparent electrode layer 53. Depending on whether the central emission wavelength is set to red, green, or blue, the resonator length, the light emitting layer material, and the like are optimized.

  FIG. 20 shows the spectrum waveforms when the resonator structure is given to the light emitter 13R (13G, 13B) and when it is not, as shown in Applied. Physics Letters Vol. 68 p2633-2635 (1966). It is. The curve with “resonator structure” has a narrower half-value width and a sharp peak than that of “without resonator structure”. For this reason, the purity of light (red, green, and blue light) emitted from the light emitter itself can be increased by providing the light emitter 13R (13G, 13B) with a resonator structure. For this reason, unnecessary wavelength components other than the desired wavelength are reduced, and high-quality color display becomes possible.

  FIG. 21 shows the directivity between when the light emitting body 13R (13G, 13B) has the resonator structure and when it is not, as shown in the same document. The directivity of “with resonator structure” is sharper in the front direction of the light source than that of “without resonator structure”. For this reason, an image with high front luminance can be provided by providing a resonator structure.

(Seventh embodiment)
A seventh embodiment will be described with reference to FIGS. This embodiment relates to a mechanism for determining deterioration of a light emitter using an organic EL element.

  It has been found that a luminous body using an organic EL element gradually deteriorates as a natural phenomenon with the lapse of its driving time, and the luminance gradually decreases. This qualitative decline is shown in FIG. As shown in the figure, the relationship between the driving time and the luminance decreases almost linearly when the vertical and horizontal axes are plotted logarithmically. In addition, the light emitting layer structure of the organic EL element is normally driven with a constant current, but the relationship between the driving time and the terminal voltage of the light emitting layer structure is qualitatively expressed as shown in FIG. That is, the terminal voltage gradually increases as the driving time increases and deteriorates. Note that the degree of fine change such as the slope of the characteristics shown in FIGS.

  Furthermore, FIG. 24 shows the qualitative relationship between the current flowing through the light emitting film structure of the organic EL element and the light emission luminance. That is, as shown in the figure, when the vertical axis and the horizontal axis are plotted logarithmically, the light emission luminance changes almost linearly with respect to the current.

  Based on these situations, the liquid crystal projector as the projection display apparatus according to the present embodiment connects the measurement / control circuit shown in FIG. 25 to the light emitter 13R (13G, 13B). A constant current source 60 is connected between the electrodes of the light emitting film structure LT of the light emitter 13R (13G, 13B), and is driven at a constant current. The constant current source 60 can change a constant current value to be flowed by a control signal.

  A voltmeter 61 for measuring the terminal voltage between the electrodes is connected between the electrodes of the light emitting film structure LT. The measurement signal of the voltmeter 61 is converted into a digital quantity by the A / D converter 62 and taken into the CPU 63. The CPU 63 is connected to an LED 64 for notifying the replacement timing of the light emitter, and to a D / A converter 65. The CPU 63 performs the processing of FIG. 26 to turn on the LED 64, while sending a control signal to the constant current source 60 via the D / A converter 65 to control the constant current value.

  An example of the control operation of the CPU 63 will be described with reference to FIG. This control is executed as interruption processing every predetermined time and every color, for example, every hour.

  The CPU 63 first reads the measured voltage value of the voltmeter 61 via the A / D converter 62 (step S1). Next, the integrated value of the drive time corresponding to the measured voltage value is inversely calculated by referring to the curve table shown in FIG. 23 (step S2). Next, by referring to the curve table shown in FIG. 22, the luminance B corresponding to the integrated value of the driving time is inversely calculated (step S3).

  Subsequently, it is determined whether or not the obtained luminance B is equal to or exceeds the preset allowable luminance value B0 (step S4). If NO in this determination, that is, if B <B0, the luminance is lower than the allowable value and the image of that color is dark, so it is better to immediately turn on the LED 64 and replace the light emitter. (Step S5).

  On the contrary, when the determination in step S4 is YES, it is determined based on the luminance values of the three colors whether the color balance of red, green, and blue is as set (step S6). When the color balance is not in the set state (NO), the driving current value for obtaining a desired luminance value is inversely calculated with reference to the curve table shown in FIG. 24 (step S8). Therefore, the CPU 63 sends a control signal for obtaining the drive current value to the constant current source 60 via the D / A converter 65. As a result, the drive current value is corrected, and the desired luminance value of the color that the light emitter 13R (13G, 13B) is in charge of is obtained.

  By monitoring the terminal voltage of the illuminant in this way, it is possible to automatically and accurately notify the replacement period of the illuminant, facilitating maintenance, and ensuring a bright screen at all times. In addition, since the color balance is automatically corrected from the terminal voltage value, a stable and high-quality screen is always provided.

  In the processing of FIG. 25 described above, the inverse calculation related to FIGS. 22 to 24 does not necessarily have to be referred to a table, and may be obtained by calculation from an approximate curve (straight line) each time. As a simpler method, the integrated value of the driving time is obtained from the terminal voltage value without obtaining the luminance value, and this integrated value is compared with the limit value of the driving time that can be determined empirically, and the comparison result is convenient. Alternatively, the lifetime of the light emitting layer may be determined.

  In addition, the configuration and means of each of the embodiments described above may be combined in any appropriate manner, and by combining these, the overall size of the liquid crystal projector can be reduced, the weight can be reduced, a bright screen with high brightness, and maintenance and inspection can be performed. The various effects described above, such as ease, can be further enhanced.

(Eighth embodiment)
A first embodiment will be described with reference to FIG. The present embodiment relates to a light source and a light source control method and apparatus. FIG. 1 is a cross-sectional view including a schematic configuration of a light source.

  The light emitting body 100 is configured such that a transparent electrode film 102 serving as an anode, an organic light emitting layer 103 and a metal electrode film 104 serving as a cathode are sequentially laminated on a glass substrate 101 and sealed with a sealing substrate 105. The planar size of the light emitter 100 depends on the object to be illuminated, but can be, for example, about 30 mm × 25 mm.

  Further, a heat sink 106 is provided on the sealing substrate 105 of the light emitting body 100 via a grease 109 having good thermal conductivity. A flat-plate electronic cooling element 107 using the Peltier effect is attached to the heat sink 106 via a grease 109 having good thermal conductivity. Note that the sealing substrate 105 constituting the light emitter 100 may also serve as the heat sink 106, and the electronic cooling element 107 is air-cooled by the fan 108.

  A thermocouple serving as a temperature sensor 110 is embedded in the heat sink 106 in order to measure the temperature of the heat sink. As the temperature sensor 110, a thermistor or the like can be used in addition to the thermocouple, and the temperature sensor may be attached to the heat sink without being embedded in the heat sink.

  The temperature switch circuit can drive and control a lighting switch 112 for turning on and off the light emitter 100 and a cooling switch 114 for supplying or not supplying power to the electronic cooling element 107. The positive pole of the DC power supply 113 is connected to the transparent electrode, and the negative pole of the DC power supply 113 is connected to the metal electrode film 104 via the lighting switch 112. The positive pole of the DC power supply 115 is directly connected to the electronic cooling element 107 via the cooling switch 114.

  By applying a DC voltage from a DC power source 113 to the transparent electrode film 102 and the metal electrode film 104, the organic light emitting layer 103 emits light, and the emitted light 116 is emitted toward the glass substrate 101.

  Although the organic light emitting layer 103 may be a single layer, a stacked structure of a charge transport layer made of an organic film and an organic light emitting film is often used.

  Next, a method for controlling the light source device will be described.

  First, the procedure for lighting the organic EL planar light source to illuminate the object to be illuminated will be described.

  Before turning on the light emitter 100, the cooling switch 114 is closed and the electronic cooling element 107 is first activated. The electronic cooling element 107 is driven by a DC power source 115 to gradually cool the heat sink 106 and the light emitting body 100.

  The temperature of the heat sink 106 is monitored by the temperature sensor 110, and when the heat sink 106 reaches a certain set temperature, for example, 10 degrees C, the temperature switch circuit 111 closes the lighting switch 112 of the organic EL planar light source.

  By closing the lighting switch 112, power is supplied to the light emitter 100 from the DC power supply 113, and the light emitter 100 emits light.

  If the light emitter 100 is turned on before the light emitter 100 is sufficiently cooled, the temperature of the organic EL element is remarkably increased, and the organic EL element is further deteriorated, for example, the luminance is decreased in a short time.

  On the other hand, if the organic EL element is cooled too much, the surface and side surfaces of the organic EL element are dewed. This dew causes changes in the radiation pattern of the emitted light and causes changes in the characteristics of the organic film that tend to change in characteristics due to humidity. Become.

  Even if the light-emitting body 100 is cooled by the electronic cooling element 107, if the organic EL element is lit, the temperature of the organic EL element is in a steady state at a temperature higher than the temperature of the heat sink 106 due to the heat generated in the organic EL element. Therefore, there is no dew on the light source.

  Next, a procedure for turning off the organic EL planar light source in order to stop the illumination of the object to be illuminated will be described.

  First, the current supplied to the organic light emitting layer 103 constituting the light emitter 100 is reduced to lower the light emission luminance. The cooling switch 114 is opened almost simultaneously with lowering the light emission luminance to stop the supply of electric power to the electronic cooling element 107 and stop the cooling.

  At this time, the current flowing through the organic light emitting layer 103 may be such that the organic light emitting layer is slightly shining, and the light emitter 100 only needs to generate heat to the extent that the surface of the light emitter 100 is not dewed.

  Here, when a large current is passed through the organic light emitting layer 103, the cooling is stopped, so that the temperature of the light emitting body 100 rises and the deterioration of the function as a light source is accelerated.

  When the temperature of the heat sink 106 rises to a set temperature, for example, 10 degrees C., the lighting switch 112 is opened to stop the supply of current to the organic light emitting layer 103, and the organic EL element is turned off.

  If the light-emitting body 100 is turned off and the electronic cooling element 107 is stopped at the same time instead of the procedure described here, the heat sink 106 remains cooled and the heat generation of the light-emitting element 100 is stopped. Is cooled and dew is generated.

  In the configuration of the light source according to the present embodiment, a sheet having high thermal conductivity can be interposed instead of the grease 109 interposed between the sealing substrate 105 and the heat sink 106 of the light emitting body 100. In this case, it becomes easy to remove the organic EL planar light source 100 from the heat sink 106, and the replacement of the organic EL planar light source 100 is facilitated.

(Ninth embodiment)
A ninth embodiment will be described with reference to FIG. The present embodiment relates to an application of the eighth embodiment to a projection display device. FIG. 2 is a schematic sectional view of a main optical system constituting the projection display apparatus.

  For the projection display device, the same or equivalent components as those described in the first embodiment are given the same reference numerals, and the device for realizing the control method of the light source device is the eighth embodiment. Constituent elements that are the same as or equivalent to those described in the embodiments are given the same reference numerals, and descriptions thereof are omitted or simplified. This description is the same in the tenth embodiment and the subsequent embodiments.

  Images displayed on the red display liquid crystal panel 12R for displaying the red component image, the green display liquid crystal panel 12G for displaying the green component image, and the blue display liquid crystal panel 12B for displaying the blue component image are dichroic. After combining by the prism 15, the image is enlarged by the projection lens 16 and displayed on the screen 17.

  In order to make the figure easy to see, the structure of the liquid crystal panel and the projection lens is not drawn, but is drawn as a block.

  As the screen 17, either a reflective screen or a transmissive screen can be applied.

  The red display liquid crystal panel 12R is illuminated by a red light emitter 100R that emits red light disposed on the back surface thereof. The light emitter 100R has a structure as shown in FIG. 27, for example, and is cooled by a cooling mechanism including a heat sink 106, an electronic cooling element 107, and a fan 108 as shown in FIG. In FIG. 28, the grease, the temperature sensor, and the temperature switch circuit depicted in FIG. 27 are omitted for easy understanding of the drawing, but the electronic cooling element 107 is controlled by the control method as described in the eighth embodiment. Starting and stopping, and turning on and off of the organic EL planar light source are controlled.

  Similarly, for the green display liquid crystal panel 12G and the blue display liquid crystal panel 12B, a green light emitting body 100G that emits green light is provided on the back surface of the green display liquid crystal panel 12G, and a back surface of the blue display liquid crystal panel 12G. A blue light emitting body 100B that emits blue light is disposed, and each organic EL planar light source is cooled by the cooling mechanism as described in the eighth embodiment.

(Tenth embodiment)
A tenth embodiment will be described with reference to FIG. The present embodiment relates to a light source and a light source control method and apparatus. FIG. 29 is a cross-sectional view showing a schematic configuration of a light source.

  The configuration of the light source of the eighth embodiment shown in FIG. 27 is the same as the configuration of the other components except that the position of the temperature sensor 110 is different.

  The temperature sensor 110 detects the temperature of the light emitter 100 and includes a temperature switch circuit 111 that controls the lighting switch 112 of the light emitter 100 or the cooling switch 114 of the electronic cooling element 107 according to the temperature.

  Next, a light source control method will be described.

  First, the procedure for lighting the organic EL element to illuminate the object to be illuminated will be described.

  Before the light emitter 100 is turned on, the electronic cooling element 107 is first activated. The electronic cooling element 107 is driven by a DC power source 115 to gradually cool the heat sink 106 and the light emitter 100.

  The temperature of the light emitter 100 is monitored by a temperature sensor 110, and the lighting switch 112 is closed by the temperature switch circuit 111 when the light emitter 100 reaches a certain set temperature, for example, 10 degrees C.

  By closing the lighting switch 112, power is supplied to the light emitter 100 from the DC power supply 113, and the light emitter 100 emits light.

  Next, a procedure for turning off the organic EL element in order to stop the illumination of the object to be illuminated will be described.

  First, the current supplied to the organic light emitting layer 103 constituting the light emitter 100 is reduced to lower the light emission luminance. The cooling switch 114 is opened almost simultaneously with lowering the light emission luminance to stop the supply of power to the electronic cooling element 107 and stop the cooling. At this time, the current flowing through the organic light emitting layer 103 may be such that the organic light emitting layer 103 is slightly shining, and the organic EL element only needs to generate heat so that the surface of the light emitting body 100 is not dewed.

  After the cooling is stopped, the heat sink 106 cools the light emitter 100 for a while, but when the temperature of the heat sink 106 starts to rise, the temperature of the light emitter 100 also starts to rise.

  When the temperature of the light emitter 100 rises to a set temperature, for example, 10 degrees C., the lighting switch 112 is opened to stop the supply of current to the organic light emitting layer 103, and the organic EL element is turned off.

  In the eighth embodiment and the tenth embodiment, the temperature sensor is attached only to either the heat sink or the organic EL element. However, the temperature sensor is attached to both and cooled while monitoring the temperature of both the heat sink and the organic EL element. It is also possible to control the timing of starting and stopping and turning on and off the organic EL element.

(Eleventh embodiment)
An eleventh embodiment will be described. The present embodiment relates to a projection type liquid crystal display device to which a control device for a light source device is applied.

  In short, the eleventh embodiment is an application of the tenth embodiment to a projection display device.

(Twelfth embodiment)
A twelfth embodiment will be described with reference to FIG. The present embodiment relates to a light source and a light source control method and apparatus. FIG. 30 is a cross-sectional view showing a schematic configuration of the light source.

  In the light source of the eighth embodiment shown in FIG. 27, the temperature sensor 110 and the temperature switch circuit 111 are removed, and a timer circuit 121 is provided instead. Other components, that is, the light emitter 100, the heat sink 106, the electronic cooling element 107, and the fan 108 are the same as those in the eighth embodiment.

  The timer circuit 121 controls the lighting switch 112 of the light emitter 100 or the cooling switch 114 of the electronic cooling element 107.

  A light source control method will be described.

  First, the procedure for lighting the organic EL planar light source to illuminate the object to be illuminated will be described.

  Before turning on the light emitter 100, the cooling switch 114 is closed and the electronic cooling element 107 is first activated. The electronic cooling element 107 is driven by a DC power source 115 and gradually cools the heat sink 106 and the organic EL planar light source 100.

  The timer circuit 121 measures the elapsed time from the time when the cooling switch 114 is closed, and the lighting switch 112 connected to the light emitter 100 is closed when a set time has elapsed from the time when the cooling switch 114 is closed. .

  By closing the lighting switch 112, the light source 100 is connected to the DC power source 113. Power is supplied and the light emitter 100 emits light.

  By measuring in advance the temperature change of the light emitter 100 after the start of cooling, it is possible to obtain the time from when the cooling switch 114 is closed until the light emitter 100 reaches a set temperature. Based on this, the time from closing the cooling switch 114 to closing the lighting switch 112 can be set.

  Next, a procedure for turning off the light emitter 100 in order to stop the illumination of the object to be illuminated will be described.

  First, the current supplied to the organic light emitting layer 103 constituting the light emitter 100 is reduced to lower the light emission luminance. The cooling switch 114 is opened almost simultaneously with lowering the light emission luminance to stop the supply of electric power to the electronic cooling element 107 and stop the cooling.

  When a set time has elapsed from when the cooling switch 114 is opened, the lighting switch 112 connected to the light emitter 100 is opened, and the light emitter 100 is turned off.

  By measuring in advance the temperature change of the organic EL element after the cooling is stopped, the time until the organic EL element reaches a set temperature after the cooling switch 114 is opened to stop the cooling is obtained. Based on this time, the time from when the cooling switch 114 is opened to when the lighting switch 112 is opened can be set.

  In the configuration of the light source according to the present embodiment, a sheet having high mature conductivity may be interposed instead of the grease 109 interposed between the sealing substrate 105 and the heat sink 106 of the light emitter 100. In this case, it becomes easy to remove the light emitter 100 from the heat sink 106, and the light emitter 100 can be easily replaced.

(13th Embodiment)
A thirteenth embodiment will be described. This embodiment relates to an application of the twelfth embodiment to a projection display device.

  That is, the thirteenth embodiment is for explaining an example in which the twelfth embodiment is applied to the projection display apparatus shown in FIG.

  In the above, the light source device of the present invention, the control method and apparatus of the light source device, and the display device to which the control method and apparatus are applied have been described. Various configurations and control methods can be considered in the gist of the present invention that the cooling timing and the lighting timing of the light source device are shifted in order to sufficiently cool the organic EL element while suppressing condensation on the organic EL element. . For example, it is possible to consider a configuration and control method that includes both a timer circuit and a temperature switch circuit and uses a temperature switch circuit when the organic EL element is turned on and a timer circuit when the organic EL element is turned off.

  Also, by providing a humidity sensor, it is possible to change the set temperature or set time according to the humidity.

(Industrial applicability)
As described above, according to the projection display apparatus of the present invention, the light emitting body having the organic EL element as the light emitting layer is used, the cooling means, the detachable mounting means, and the means for adjusting the directivity of the emitted light. Since it is possible to provide means for increasing the light emission efficiency, adoption of a resonator structure, automatic life determination means, etc., it is possible to overcome the problems that have been difficult to overcome in the past. It is possible to provide a projection display device that employs a light emitter made of an element.

  In particular, by installing a cooling means using an electronic cooling element or a heat radiating fin in the light emitter, it is possible to suppress a decrease in light emitting performance due to heat generation of the organic EL element, to extend the life, stabilize the luminance, and The highest brightness can always be secured.

  In addition, by providing attachment means for detachably attaching the light emitter to the base portion on which the liquid crystal panel and the light emitter are placed, the light emitter by the organic EL element can be electrically connected and optically independently for each light emitter. It is possible to easily replace the product in a state where the target position is secured, thereby improving the efficiency of replacement work and facilitating maintenance and inspection.

  Furthermore, the terminal voltage between the electrodes of the light emitting film structure is measured, the life of the light emitting film structure is determined from the terminal voltage value, and when the life is determined, the life of the light emitter is notified. The timing for replacement can be easily determined, ensuring a high quality screen display and facilitating maintenance and inspection.

  Furthermore, by providing directivity adjusting means such as a lens array or a prism array that adjusts the directivity of the light emitted from the light emitter toward the liquid crystal panel, the light incident on the liquid crystal panel from the light emitter by the organic EL element The directivity of the light is improved, the light incident efficiency to the liquid crystal panel is improved, and a stable screen with high brightness can be provided.

  Furthermore, by integrally forming a microlens array or microprism array on the light exit surface of the transparent substrate of the light emitter, the light output efficiency from the light emitter by the organic EL element can be increased, and a stable screen with high brightness can be obtained. Can be provided.

  Furthermore, the directivity and efficiency of incident light to the liquid crystal panel can be greatly improved by providing the light emitting layer structure of the light emitter with a resonator structure that selectively emits light having a specific wavelength to resonate. .

  The light source device according to the present invention includes an organic EL element and a cooling mechanism that cools the organic EL element, and includes a temperature sensor or a timer attached to the organic EL element or the cooling means. The cooling state can be controlled.

  The light source device control method of the present invention is characterized in that the temperature of the organic EL element is monitored by a temperature sensor or the start and stop of cooling is shifted from the timing of turning on and off the organic EL planar light source by the timer. In addition, the organic EL element can be sufficiently cooled while suppressing dew condensation on the organic EL element, and deterioration of the organic EL element can be suppressed and its life can be extended.

  The controller of the light source device of the present invention controls the start / stop of cooling and the timing of turning on / off the organic EL planar light source by monitoring the temperature of the organic EL element by a temperature sensor or by the timer. As a feature, the organic EL element can be sufficiently cooled while suppressing dew condensation on the organic EL element, and deterioration of the organic EL element can be suppressed and its life can be extended.

  In addition, according to the projection display device to which the control method and apparatus for the light source device of the present invention is applied, the display device of the present invention can be remarkably miniaturized as compared with a display device using a discharge lamp as a light source.

1 is a plan view showing a schematic configuration of a liquid crystal projector according to a first embodiment of the present invention. It is a figure which shows the lamination | stacking state of the light-emitting body which used the organic EL element as the light emitting layer. It is a figure which shows the state which attached the cooling body as a cooling means to the light-emitting body. It is a top view which shows schematic structure of the liquid crystal projector which concerns on the 2nd Embodiment of this invention. It is a figure which shows the state which attached the cooling body as a cooling means to the light-emitting body. It is a figure which shows the state which attached another cooling body to the light-emitting body. It is a figure which shows the state which attached another cooling body to the light-emitting body. It is a top view which shows partially the schematic structure of the liquid-crystal projector which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the part of the guide in FIG. 8, and a connector. It is a perspective view which shows the light-emitting body of the structure which can be exchanged. It is a schematic sectional drawing in alignment with the AA in FIG. It is a top view which shows schematic structure around the light-emitting body of the liquid crystal projector which concerns on the 4th Embodiment of this invention. It is a schematic perspective view of the structure of FIG. It is a top view which shows schematic structure around the light-emitting body of the liquid crystal projector which concerns on the modification of 4th Embodiment. It is a schematic perspective view of the structure of FIG. It is a figure which shows schematic structure around the light-emitting body of the liquid crystal projector which concerns on the 5th Embodiment of this invention. It is a figure which shows schematic structure of the light-emitting body which does not provide a lens array compared with FIG. It is a modification of the 5th Embodiment of this invention, and is a figure which shows the outline | summary of a microprism array. It is a figure which shows schematic structure around the light-emitting body of the liquid crystal projector which concerns on the 6th Embodiment of this invention. It is a figure explaining the difference in the spectrum waveform by the presence or absence of a resonator structure. It is a figure explaining the difference in directivity by the presence or absence of a resonator structure. It is a graph which shows the relationship between the integral drive time and the brightness | luminance of the light-emitting body which used the organic EL element as the light emitting layer. It is a graph which shows the relationship between the integration drive time of the light-emitting body which used the organic EL element as the light emitting layer, and the terminal voltage. It is a graph which shows the relationship between the brightness | luminance and electric current value of the light-emitting body which used the organic EL element as the light emitting layer. It is a block diagram which shows an example of the measurement and control circuit of the terminal voltage of the light-emitting body of the liquid crystal projector which concerns on the 7th Embodiment of this invention. It is a flowchart which shows the process of CPU in 7th Embodiment. It is sectional drawing which shows schematic structure of the light source in the 8th Embodiment of this invention. It is a schematic sectional drawing of the main optical system which comprises the liquid crystal display device in the 9th Embodiment of this invention. It is sectional drawing which shows schematic structure of the light source in the 10th Embodiment of this invention. It is sectional drawing which shows schematic structure of the light source in the 11th Embodiment of this invention. It is a top view which shows schematic structure of the liquid crystal projector which concerns on a prior art example. It is a top view which shows schematic structure of the liquid crystal projector which concerns on another prior art example. It is a schematic perspective view of the structure of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Housing | casing, 12R, 12G, 12B ... Liquid crystal panel, 13R, 13G, 13B ... Luminescent body, 14R, 14G, 14B ... Cooling body, 15 ... Dichroic prism, 16 ... Projection lens, 17 ... Transmission type screen, 20 DESCRIPTION OF SYMBOLS ... Transparent substrate, 21 ... Transparent electrode layer, 22 ... Light emitting layer, 23 ... Reflective electrode layer, 24 ... Sealing substrate, 25 ... Thermal conductor, 26 ... Electronic cooling element

Claims (12)

A planar light source having a first electroluminescent layer that emits first light ;
A planar light source having a second electroluminescent layer that emits a second light different from the first light;
A first electronic cooling element for cooling the planar light source having the first electroluminescent layer ;
A second electronic cooling element that cools the planar light source having the second electroluminescent layer ;
A first lighting switch for controlling power supply to the planar light source having the first electroluminescent layer ;
A first cooling switch for controlling supply of power to the first electronic cooling element;
A second lighting switch for controlling power supply to the planar light source having the second electroluminescent layer ;
A second cooling switch for controlling supply of electric power to the second electronic cooling element ,
The control of the first lighting switch for starting the supply of power to the planar light source having the first electroluminescent layer is to start the supply of power to the first electronic cooling element. A light source device which is performed after the control of the first cooling switch . A planar light source having a first electroluminescent layer that emits first light ;
A first electronic cooling element for cooling the planar light source having the first electroluminescent layer ;
A first lighting switch for controlling power supply to the planar light source having the first electroluminescent layer;
A first cooling switch for controlling supply of electric power to the first electronic cooling element ,
The control of the first lighting switch for starting the supply of power to the planar light source having the first electroluminescent layer is to start the supply of power to the first electronic cooling element. A light source device which is performed after the control of the first cooling switch . A planar light source having a first electroluminescent layer that emits first light ;
A planar light source having a second electroluminescent layer that emits a second light different from the first light;
A first electronic cooling element for cooling the planar light source having the first electroluminescent layer ;
A second electronic cooling element that cools the planar light source having the second electroluminescent layer ;
A first lighting switch for controlling power supply to the planar light source having the first electroluminescent layer ;
A first cooling switch for controlling supply of power to the first electronic cooling element;
A second lighting switch for controlling power supply to the planar light source having the second electroluminescent layer ;
A second cooling switch for controlling supply of electric power to the second electronic cooling element,
The control of the first lighting switch for stopping the supply of power to the planar light source having the first electroluminescent layer is to stop the supply of power to the first electronic cooling element. A light source device which is performed after the control of the first cooling switch . A planar light source having a first electroluminescent layer that emits first light ;
A first electronic cooling element for cooling the planar light source having the first electroluminescent layer ;
A first lighting switch for controlling power supply to the planar light source having the first electroluminescent layer;
A first cooling switch for controlling supply of electric power to the first electronic cooling element ,
The control of the first lighting switch for stopping the supply of power to the planar light source having the first electroluminescent layer is to stop the supply of power to the first electronic cooling element. A light source device which is performed after the control of the first cooling switch . The light source device according to any one of claims 1 to 4 ,
A light source device including a first temperature switch that drives and controls the first lighting switch and the first electronic cooling element. The light source device according to any one of claims 1 to 5 ,
A light source device , wherein a first heat sink is disposed between a planar light source having the first electroluminescent layer and the first electronic cooling element. The light source device according to claim 6 ,
A light source device , wherein a grease having high thermal conductivity is disposed between a planar light source having the first electroluminescent layer and the first heat sink. The light source device according to claim 6 ,
A sheet having high thermal conductivity is disposed between the planar light source having the first electroluminescent layer and the first heat sink, and the planar light source having the first electroluminescent layer is removable. Light source device. The light source device according to any one of claims 6 to 8 ,
The light source device, wherein the first heat sink includes a temperature sensor. The light source device according to any one of claims 1 to 9 ,
A planar light source having the first electroluminescent layer includes a first electrode, a second electrode, and a light emitting layer positioned between the first electrode and the second electrode. A light source device including a structure. Projector, characterized in that it comprises a light source device according to any one of claims 1 to 10. Projection television, characterized in that it comprises a light source device according to any one of claims 1 to 10.

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