JP2006013127A - Light source and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, light-weight and low-power consumption light source effectively utilizable for light emitting devices having large radiation angles such as light emitting diodes, and a compact display using the same such as retina displays. <P>SOLUTION: The light source is composed of a light emitting device part 1, a condenser 10 and a multiplexing part 20. The light emitting device part 1 mounts a plurality of chip-like light emitting devices 2 and controls the emission of each light emitting device 2 independently through an external terminal 8. The condenser 10 holds spherical lenses 11 fitted into fitting holes formed in a lens stopper 13 close to a light emitter with the lenses 11 contacted to or facing at the light emitting devices 2, so as to deflect lights radiated from the light emitting devices 2 into collimated light beams before spreading. The multiplexing part 20 has a dichroic mirror 21 and apertures 24, 25 which combine the collimated light beams incident from the condenser 10 and select and emit a paraxial ray superior in parallelism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source device that can effectively use a light emitting element having a large radiation angle such as a light emitting diode, and a small display device such as a retina display device using the light source device.

  In recent years, electronic devices, particularly portable electronic devices, are required to be smaller, lighter, and more multifunctional. Under such a trend, image data is also handled in portable electronic devices such as PDAs (personal digital assistants), and it is easy to see a fine image in a large size as the size of the device advances. The issue is whether to realize the function to display.

  Since the retinal display disclosed in Japanese Patent Publication No. 11-505627 discloses an image formed on the retina of the user's eye, the area occupied by the display can be reduced, miniaturization and high-definition display. It is highly expected as a display device that can achieve both. Since the retina display is a part of a portable device or is used by connecting to a portable device, it will be possible to reduce the size and weight of color display devices that make up the display in the future. This is one of the issues.

  Conventionally, as a light source unit of a retinal display device capable of color display, for example, as shown in Patent Document 1 described later, three laser beams of R (red), G (green), and B (blue) are used. There has been proposed a technique for combining the signals using a dichroic mirror.

  FIG. 9 is an explanatory diagram showing a general configuration when a similar device is configured using a light emitting diode (LED) instead of a laser light source.

  The red light emitting element 101R, the blue light emitting element 101B, and the green light emitting element 101G are LEDs that emit light of three primary colors of R (red), G (green), and B (blue), respectively. The light from each light-emitting element is changed in its path by a condensing lens 102 disposed so as to be opposed to the light-emitting element, and enters the dichroic mirror 103 as a parallel light beam.

  The dichroic mirror 103 reflects light having a specific wavelength, and transmits light having other wavelengths. For example, the dichroic mirror 103R reflects the red light from the red light emitting element 101R and changes its path in the horizontal direction. The dichroic mirror 103B reflects the blue light from the blue light emitting element 101B and changes its path in the horizontal direction, while the red light transmitted from the dichroic mirror 103R is transmitted in the horizontal direction as it is. Further, the dichroic mirror 103G reflects the green light from the green light emitting element 101G and changes its course in the horizontal direction, while the red light and blue light sent from the dichroic mirror 103B remain in the horizontal direction. Make it transparent.

  In this way, the three primary color lights of red, green and blue are guided on the same optical axis and are superimposed, so that the light source unit 104 shown in FIG. 9 can be used as a light source of a retinal display device capable of color display. .

  The light beams combined into one by the light source unit 104 are imaged on the retina of the user's eye 107 by the scanning unit 105 and the lens 106 of the projection optical system, and form a raster image on the retina.

JP-A-7-168123 (page 4, FIG. 1)

  However, the light emitted from the LED has a large radiation angle and travels in various directions. On the other hand, light-emitting elements that are normally distributed in the market are not semiconductor chips themselves, but chips that are housed in some package. For example, there are ones housed in a metal case and hermetically sealed, and ones housed in a resin-sealed package. In such a case, since there is a distance from the light emitting portion of the light emitting element to the outer edge portion of the package, when the light beam emitted from the light emitting portion reaches the outer edge portion of the package, the light beam has already spread greatly. In order to condense the spread light beam, a condensing lens 102 having a large aperture is required. In addition, as the condenser lens 102 becomes larger, the optical adjustment mechanism for aligning the optical axes of the light emitting element 101 and the condenser lens 102 and adjusting the relative position and the space required for the adjustment also increase in size. To do.

  Further, since the light flux from the light emitting section is changed to a parallel light flux after being spread, the light density of the obtained parallel light flux decreases in inverse proportion to the spread of the light flux from the light emitting section. As a result, in order to obtain a predetermined amount of combined light, the cross-sectional area of the parallel light beam processed by the dichroic mirror 103 must be increased in inverse proportion to the decrease in light density, and the dichroic mirror 103 is also large. I need it.

  As described above, when the spread of the light flux from the light emitting unit to the condenser lens 102 increases, not only the condenser lens 102 needs to be enlarged, but also the optical components after the dichroic mirror 103 are enlarged. As a result, the entire light source unit becomes larger. As the size of the light source device increases, the weight of the light source device increases as a result. In order to reduce the size and weight of the retina display, it is first necessary to reduce the size and weight of the light source unit.

  The present invention has been made in view of such circumstances, and an object thereof is to effectively use a light emitting element having a large emission angle, such as a light emitting diode, and is a light source that is small, light, and consumes little power. An apparatus and a small display device such as a retina display device using the device.

  The present invention relates to a light source device having a light emitting element with an exposed light emitting portion and a condensing lens disposed in contact with or facing the light emitting portion of the light emitting element, and the light source device and the light source device. The present invention relates to a display device including projection means for projecting light from the display.

  According to the present invention, the light source device is configured using the light emitting element with the light emitting unit exposed and the condensing lens disposed in contact with or facing the light emitting unit of the light emitting element. For this reason, by providing the condensing lens adjacent to or facing the exposed light emitting part of the light emitting element, the path before the light flux emitted from the light emitting part spreads is improved. This light beam can be changed to a parallel light beam, for example.

  As a result, a lens having a large aperture is not necessary as the condenser lens, and for example, a spherical lens (ball lens) described later can be used. In addition, since the condenser lens is reduced in size, the optical adjustment mechanism for adjusting the optical axes of the light emitting element and the condenser lens and adjusting the relative position and the space required for the adjustment are also reduced in size. To do.

  Compared with a conventional light source device that uses a light emitting element whose light emitting portion is coated with a mold resin and the light flux from the light emitting portion spreads, the light flux spreads, for example, into a parallel light flux. Therefore, the light density of the light beam can be increased in inverse proportion to the degree of spread of the light beam by the amount that can be processed before the light beam. For this reason, in the subsequent optical device, the cross-sectional area of the light beam that must be processed in order to obtain a predetermined light amount can be reduced as the light density increases, and the subsequent optical device can be downsized. be able to.

  As described above, when the light emitting element in which the light emitting unit is exposed is used, not only the light emitting element itself can be downsized but also the subsequent optical device can be downsized, and the light emitting element and the condenser lens can be downsized. And the subsequent optical device can be reduced in size. As the optical device becomes smaller, the weight of the optical device also decreases as a result. In addition, since the light emitted from the light emitting element can be used efficiently, power consumed for light emission can be suppressed.

  In addition, since the display device of the present invention includes the light source device and projection means for projecting light from the light source device, it is possible to realize a reduction in size and weight and power consumption as in the light source device. The projecting means means means for scanning the combined light on the image forming surface and means for forming an image of the combined light.

  In the light source device of the present invention, it is preferable that the light source device includes a plurality of the light emitting elements and a multiplexing unit that multiplexes the light emitted from these light emitting elements. When the plurality of light emitting elements emit the same color of emitted light, a light flux having a higher light density can be obtained by combining the emitted light. Further, when the plurality of light emitting elements respectively emit light of a plurality of colors, multicolor or full color combined light can be obtained by combining the emitted light, and the light source of the retinal display device capable of color display It can be used as such.

  Further, it is preferable that the multiplexing means is disposed on the light exit side of the condenser lens. In this way, the condensing lens can be provided in the immediate vicinity of the light-emitting portion of the light-emitting element, and the path can be changed before the light beam spreads, for example, can be sent to the combining means as a parallel light beam. .

  At this time, the condensing lens is preferably a spherical lens (ball lens). However, in this specification, a spherical lens (ball lens) is made of a light-transmitting material and means a complete spherical lens or a lens that forms a substantially perfect spherical surface. By using a spherical lens that does not require optical axis adjustment, the mechanism and adjustment space necessary for optical adjustment are not required, and the light source device can be further downsized. In addition, the condensing lens can be easily disposed within a close distance of the light emitting portion of the light emitting element.

  Furthermore, it is preferable that the multiplexing means has an aperture provided on a substantially optical axis of the light condensed by the condenser lens. Thereby, for example, paraxial light rays having good parallelism with respect to the optical axis can be selected and used from the light fluxes whose directions are changed by the condenser lens.

  Further, the multiplexing means includes a dichroic mirror or a dichroic prism that reflects only light in a predetermined wavelength range and transmits light in other wavelength ranges out of the light collected by the condenser lens. Good. As a result, light having an unnecessary wavelength is excluded from the light emitted from the light emitting element, and only light necessary for forming the combined light is selected and combined, so that the desired color tone can be obtained. The combined light having is obtained.

  In addition, an aperture smaller than the diameter of the combined light beam may be provided substantially on the optical axis of the combined light beam at the light emission position of the combining means. In this way, it is possible to select and extract a light beam that is close to the optical axis and that is particularly excellent in parallelism among the combined light formed by the overlapping of a plurality of light beams. Further, by appropriately setting the size of the aperture, a combined light beam having a beam diameter required as a light source can be obtained.

  The plurality of light emitting elements may be any of a red light emitting element, a green light emitting element, and a blue light emitting element. Multi-color or full-color combined light can be obtained by combining light emitted from these light-emitting elements.

  Further, it is preferable that the light emission amounts of the plurality of light emitting elements are individually controlled. By supplying driving power to each of the light emitting elements, the plurality of mounted light emitting elements can emit light with independent light emission amounts. For example, by independently controlling the light emission amounts of the red light emitting element, the green light emitting element, and the blue light emitting element, it is possible to obtain a full color combined light by mixing the three primary color lights, and the projection means generates a full color image. Can be formed.

  Since the display device of the present invention is small and lightweight, it is particularly preferable to be configured as a retinal display device.

  Next, a preferred embodiment of the present invention will be described specifically and in detail with reference to the drawings.

Embodiment 1
FIG. 1 is an explanatory diagram showing a general configuration of a light source device of a retinal display capable of color display based on the first embodiment. 1A is a cross-sectional view of the light emission side, and FIG. 1B is a cross-sectional view at the position indicated by the line 1A-1A in FIG. In FIG. 1, in order to make it easy to see, some hatching such as a spherical lens (ball lens) and a dichroic mirror is omitted (the same applies hereinafter).

  The light source device mainly includes a light emitting element unit 1, a light collecting unit 10, and a multiplexing unit 20. A plurality of chip-like light emitting elements 2 such as LEDs and laser diodes can be mounted on the light emitting element unit 1, and the light emission of each light emitting element 2 can be electrically controlled through the external terminal 8. The condensing unit 10 can hold the same number of ball lenses (ball lenses) 11 as the number of mounted light emitting elements 2. Similarly, the multiplexing unit 20 can hold the same number of dichroic mirrors 21. FIG. 1 shows an example in which the number of light emitting elements to be mounted is three as an example, but the number of mounted elements is not limited to this, and is appropriately selected. The detailed structure and function of each part will be described below.

  FIG. 2 illustrates the structure of the light-emitting element portion 1. FIG. 2A is a cross-sectional view of the light emitting side, and FIG. 2B is the same as FIG. 1B. It is sectional drawing in the position of -1A line.

  In the light emitting element unit 1, chip-shaped red light emitting element 2R, blue light emitting element 2B, and green light emitting element 2G that emit light of three primary colors of R (red), G (green), and B (blue), respectively. Is mounted on the sub-board 3. The sub-substrate 3 is provided with a mark serving as a reference position for ensuring the positioning accuracy of the light emitting element 2 and a pattern for fixing the chip-like light emitting element 2.

  On the support bottom 4, there is provided a land 6 that is slightly larger than the sub-board 3 and is a base for mounting the sub-board 3. The sub-board 3 is fixed to the land 6. In addition to the lands 6, conductive lands 7 for forming electrical wirings 9 by wire bonding or the like are provided on the support bottom 4.

  The support bottom portion 4 and the support side portion 5 are integrally formed to form a box-shaped container, in which a light collecting portion 10 described later is accommodated. The support bottom 4 is, for example, a substrate made of a ceramic material on which pattern wiring such as lands 6 and lands 7 is formed by plating or the like, or a lead frame patterned in the shape of the lands 6 and lands 7. A material produced by molding the metal material together with a resin can be used, and general mounting substrate manufacturing techniques can be applied.

  The land 7 is electrically connected to an external terminal 8 disposed on the outer surface of the support bottom 4 through a through-hole wiring (not shown) formed on the support bottom 4. The land 6 is connected to the external terminal 8 or connected to the land 7 by wire bonding depending on the package structure. By supplying driving power to each light emitting element 2 through the external terminal 8, the plurality of mounted light emitting elements 2 can emit light. Further, by independently controlling the light emission amounts of the red light emitting element 2R, the blue light emitting element 2B, and the green light emitting element 2G, it is possible to obtain full color combined light by mixing the three primary color lights.

  An inexpensive LED is suitable as the light emitting element 2 used in the light source device. Among these, surface-emitting LEDs are preferred because they are easy to manufacture, excellent in high frequency characteristics, easily modulated, and easy to mount. A VCSEL (vertical cavity surface emitting laser) may be used.

  FIG. 3 is a perspective view showing the electrode shape of the surface-emitting LED and the state of electrical connection. When electrodes are provided on the top and bottom as shown in FIG. 3A, the upper electrode 61 is connected to the land 7 by wire bonding wiring 9, and the bottom lower electrode 62 is wiring on the sub-substrate 3. The pattern 63 is connected with a conductive resin (not shown). In order to connect this to the outside, the wiring pattern 63 drawn on the sub-board 3 and the land 7 are connected by the wire bonding wiring 9. When two electrodes are provided on the upper portion as shown in FIG. 3B, each electrode is connected to the land 7 by the wire bonding wiring 9.

  4A and 4B illustrate the structure of the light collecting unit 10. FIG. 4A is a cross-sectional view of the light emitting side, and FIG. 4B is the same as FIG. 1B. It is sectional drawing in the position of -1A line.

  In the condensing unit 10, the same three spherical lenses (ball lenses) 11 as the number of the light emitting elements 2 mounted are held by the lens holder 12 and the lens stopper 13. The spherical lens 11 is a complete sphere made of a translucent material. The lens holder 12 is formed by, for example, resin molding or metal processing, has a slightly larger cross section than the ball lens 11, and can hold, for example, three ball lenses 11. The resin material is preferably a light and strong resin, such as a liquid crystal polymer resin mixed with a material used as a liquid crystal polymer.

  A lens stopper 13 that is similarly formed of the same kind of material as the lens holder 12 is provided below the lens holder 12. The lens stopper 13 is provided with a fitting hole 14 having a size smaller than the outer shape of the spherical lens 11. The fitting hole 14 is, for example, circular, but is not limited thereto, and may be any shape that can support the ball lens 11 at three or more points, and may be, for example, a square hole.

  According to such a lens holder 12 and the lens stopper 13, the ball lens 11 can be positioned by self-alignment based on the outer shape simply by dropping the ball lens 11 into each lens holder 12.

  That is, the spherical lens 11 introduced into the lens holder 12 can only fall into the fitting hole 14 provided in the lens stopper 13, and the spherical lens 11 is automatically fitted by the concave and convex fitting between the spherical lens 11 and the fitting hole 14. 11 is positioned and held, and the position of the center of the sphere is determined. Thereby, the distance between the spherical lens 11 and the light emitting element 2 and the position of the optical axis (the central axis of the spherical lens in the vertical direction in FIG. 4) 15 of the spherical lens 11 are also automatically determined. There is no need to make an optical adjustment such as adjusting the relative position to 2 or aligning the optical axis.

  The spherical lens 11 can obtain the accuracy of the position of the optical axis 15 following the center of the fitting hole 14. Accordingly, what relates to the positioning accuracy of the optical axis 15 of the spherical lens 11 is the sphericity of the spherical lens 11 and the positioning accuracy of the center of the fitting hole 14 provided in the lens stopper 13. All of these can realize high accuracy relatively easily without taking time and effort.

  Further, the spherical lens 11 can obtain the position accuracy in the vertical direction according to the size of the fitting hole 14. Therefore, the accuracy of the distance between the ball lens 11 and the light emitting element 2 is the accuracy of the outer dimensions of the ball lens 11 and the accuracy of the diameter of the fitting hole 14 provided in the lens stopper 13. These can also achieve high accuracy relatively easily without trouble.

  In this way, the sphericity of the spherical lens 11 and the accuracy of the outer dimensions are managed to be high, and the center position of the fitting hole 14 provided in the lens stopper 13 and the precision of the dimensions are managed to be high, so that the optical adjustment is possible. The ball lens 11 can be positioned with high accuracy without the trouble of performing the above. Since the above management is relatively easy, it is possible to manufacture a light source device with a high yield, a low efficiency, and a low cost.

  In order to fix the positioned ball lens 11, a not-shown holding lid may be placed on the ball lens 11 from above or may be bonded and fixed to the lens holder 12 using an adhesive. Further, it is preferable to provide a light shielding wall 16 between the space regions that accommodate the spherical lenses 11 so that stray light from the respective spherical lenses 11 does not affect each other.

  FIG. 5 illustrates the structure of the multiplexing unit 20. FIG. 5 (a) is a cross-sectional view of the light emitting side, and FIG. 5 (b) is the same as 1A in FIG. 1 (b). It is sectional drawing in the position of -1A line.

  In the multiplexing unit 20, the same three dichroic mirrors 21 </ b> R, 21 </ b> B, and 21 </ b> G as the number of mounted light emitting elements 2 are held by the mirror holder 23. The dichroic mirror 21R reflects only red light and transmits other light. Similarly, the dichroic mirror 21B reflects only blue light and transmits other light, and the dichroic mirror 21G reflects only green light and transmits other light.

  The dichroic mirror 21R is obtained by, for example, dividing a rectangular parallelepiped made of a transparent material such as glass into two triangular prisms, and forming a red light reflecting surface 22R that reflects only red light on the cut surface of one triangular prism. The red light reflecting surface 22R can be formed by depositing a dielectric multilayer film. Similarly, the dichroic mirrors 21B and 21G divide a rectangular parallelepiped made of a transparent material such as glass into two triangular prisms, and only the blue light reflecting surface 22B and the green light reflecting only the blue light on the cut surface of one triangular prism. The green light reflecting surfaces 22G that reflect the light are respectively formed. The mirror holder 23 is formed by, for example, resin molding or metal processing.

  A small-diameter aperture 24 is provided on the incident side to each dichroic mirror 21R, 21B, and 21G. A smaller diameter aperture 25 is also provided on the side from which the combined light combined by the dichroic mirrors 21R, 21B, and 21G is emitted.

  FIG. 6 is an explanatory diagram illustrating the configuration of an optical path from when the green light emitting element 2G is selected as an example of the three light emitting elements 2 until the light emitted from the green light emitting element 2G is emitted from the aperture 25.

  The green light emitting element 2G is an LED having a minute chip size of about 0.2 mm square, for example. A spherical lens 11 having a diameter of about 2 mm, for example, is disposed opposite to the green light emitting element 2G as close as possible. The gap D between the green light emitting element 2G and the spherical lens 11 is 0 to about 0.5 mm, and the smaller the better, the both may be in contact with each other. A light beam emitted from a light emitting element such as an LED is diffused light having a large radiation angle. However, when the gap D is arranged as small as possible, the light emitted from the green light emitting element 2G is efficiently used. The light beam is incident on the spherical lens 11 and its optical path is refracted to the optical axis side, and the optical path can be changed so that the light beam emitted from the spherical lens 11 is a beam close to a parallel light beam parallel to the optical axis.

  At this time, the wiring by wire bonding or the like provided on the light emitting element 2 such as an LED is arranged in a loop shape with a low height so that the spherical lens 11 can be brought into contact with the surface of the light emitting element 2 or just before it. It is good to make it. Further, the method of supporting the spherical lens 11 with the lens stopper 13 having the circular fitting hole 14 shown in FIG. 4 does not obstruct the approach between the light emitting element 2 and the spherical lens 11, and It is also suitable for the purpose.

  A small-diameter aperture 24 is provided in the mirror holder 23 on the side where light enters the dichroic mirror 21G. The aperture 24 is provided on the optical axis 15 of the ball lens 11 and, among the light beams emitted from the ball lens 11, a light beam that is particularly close to the optical axis 15 and closer to a parallel light beam is selected to be a dichroic mirror. It works to send to 21G. Depending on the size of the aperture 24, the beam diameter of the parallel light beam to be sent to the multiplexing unit 20 can be set as appropriate. For example, the aperture 24 having a diameter of 0.4 to 0.5 mm may be provided.

  The parallel light beam incident on the dichroic mirror 21G is reflected by the green light reflecting surface 22G and proceeds in the horizontal direction toward the emission side. On the other hand, the red light and blue light transmitted from the dichroic mirror 21B are transmitted through the dichroic mirror 21G in the horizontal direction. In this manner, the light beams of green light, red light, and blue light are guided on the same optical axis, and in the vicinity of the emission side aperture 25, a beam of combined light is formed by the overlap of the three beams. Of these, a light beam close to the optical axis and particularly excellent in parallelism is preferably selected and extracted with an aperture 25 smaller than the beam diameter of the combined light. By appropriately setting the size of the aperture 25, a combined light beam having a beam diameter required as a light source can be obtained. For example, the diameter of the aperture 25 may be set to be equivalent to the pixel size of the virtual screen such as 10 to 20 μm.

  Although illustration is omitted, if the gap D is doubled, for example, the light reaching the spherical lens 11 from the green light emitting element 2G spreads several times, and the light beam light that can be extracted from the aperture 24 or the aperture 25 It can be easily imagined that the density drops to a fraction. In order to compensate for the decrease in light density on the light emitting element 2 side, it is necessary to illuminate the light emitting element 2 with several times the brightness, and for this purpose, the power consumption is increased many times. As can be seen from such considerations, it is extremely important to make the gap D close to 0 in the light utilization mode as shown in FIGS. 1 and 6.

  As described above, according to the present embodiment using the light emitting element in which the light emitting part is exposed, the light density is much higher than that of the light source device using the conventional light emitting element in which the light emitting part is coated with a mold resin or the like. Parallel beam can be taken out. As a result, the cross-sectional area of the parallel beam to be processed to obtain a predetermined amount of combined light can be reduced as the light density increases, and the combining means can be downsized. can do.

  As described above, when the light emitting element in which the light emitting portion is exposed is used, not only the light emitting element itself can be miniaturized, but also the multiplexing means can be miniaturized and the entire light source device can be miniaturized. When the light source device is downsized, the weight of the light source device is reduced as a result.

  Next, the operation of the light source device shown in FIG. 1 will be described based on the structure and function features of the respective parts described above.

  The red light emitting element 2R, the blue light emitting element 2B, and the green light emitting element 2G are supplied with three primary color lights of R (red), G (green), and B (blue) when driving power is supplied through the external terminal 8, respectively. Emits light. The light from each light emitting element is changed in its path by the spherical lens 11 disposed so as to be opposed to the light emitting element, and is sorted by the aperture 24 to become a parallel light beam having a beam diameter of 0.4 to 0.5 mm to the dichroic mirror 21. Incident.

  The dichroic mirror 21R reflects the red light from the red light emitting element 2R and changes its path in the horizontal direction. Further, the dichroic mirror 21B reflects the blue light from the blue light emitting element 2B and changes its path in the horizontal direction, while the red light transmitted from the dichroic mirror 21R is transmitted as it is in the horizontal direction. The dichroic mirror 21G reflects the green light from the green light emitting element 2G and changes its path in the horizontal direction, while the red light and blue light transmitted from the dichroic mirror 21B are transmitted in the horizontal direction as they are. Let

  In this way, the three primary color lights of red, green and blue are guided on the same optical axis, and a beam of combined light is formed in the vicinity of the emission side aperture 25 by the overlap of the three primary color lights. Among these, a light beam close to the optical axis and particularly excellent in parallelism is selected by the aperture 25, and is extracted as a parallel light flux having a beam diameter of 10 to 20 μm, for example.

  The emitted combined light beam is a high-quality light in which light having extremely excellent parallelism near the optical axis is selected. Further, since the light emitted from the light emitting element 2 is converted into a parallel light flux by the spherical lens 11 before spreading, the light density of the combined light beam is high. Such a light source structure is suitable for increasing the light amount of a light source that emits a light beam having a very small beam diameter, and the characteristics of the emitted light are suitable for application to a retina display or the like.

  Further, by independently controlling the driving power supplied to each light emitting element, the light emission amounts of the red light emitting element 2R, the blue light emitting element 2B, and the green light emitting element 2G can be controlled independently, It is possible to obtain full color combined light by color mixing. This emitted beam can be used as a light source of a display device capable of full color display.

  As described above, when a chip-like light emitting element having an exposed light emitting portion is used, not only the light emitting element itself can be miniaturized, but also the multiplexing means can be miniaturized and the entire light source device can be miniaturized. When the light source device is downsized, the weight of the light source device is reduced as a result. In addition, since the light emitted from the light emitting element can be used efficiently, power consumed for light emission can be suppressed.

  Further, by using a spherical lens that does not require optical axis adjustment as a condensing lens, a mechanism and adjustment space necessary for optical adjustment are not required, and the light source device can be further downsized. In addition, the condensing lens can be easily disposed within a close distance of the light emitting portion of the light emitting element.

  The accuracy of the sphericity and outer dimensions of the spherical lens 11 is managed to be high, and the center position of the fitting hole 14 provided in the lens stopper 13 and the precision of the dimensions are managed to be high, so that the trouble of performing optical adjustment is reduced. The ball lens 11 can be accurately positioned without applying. Since the above management is relatively easy, it is possible to manufacture a light source device with a high yield, a low efficiency, and a low cost.

Embodiment 2
FIG. 7 is an explanatory diagram showing a general configuration of a light source device of a retinal display capable of color display based on the second embodiment. FIG. 7A is a cross-sectional view in the same direction as FIG. 1A, and FIG. 7B is a cross-sectional view at the position indicated by the line 7B-7B in FIG. 7A.

  This light source device is configured in substantially the same manner as the light source device according to the first embodiment shown in FIG. However, it differs from the light source device shown in FIG. 1 only in that the configuration of the multiplexing unit is slightly changed so that the combined light can be extracted upward from the aperture provided in the central upper surface. Hereinafter, in order to avoid duplication, it demonstrates focusing on difference.

  The light source device shown in FIG. 7 mainly includes a light emitting element unit 1, a condensing unit 10, and a combining unit 30. A plurality of chip-like light emitting elements 2 such as LEDs and laser diodes can be mounted on the light emitting element unit 1, and the light emission of each light emitting element 2 can be electrically controlled through the external terminal 8. The condensing unit 10 can hold the same number of ball lenses (ball lenses) 11 as the number of mounted light emitting elements 2. These are the same as the light emitting element portion 1 and the light collecting portion 10 of the apparatus shown in FIG.

  In the multiplexing unit 30, prism mirrors 31R and 31G are held by the mirror holder 23 instead of the dichroic mirrors 21R and 21G used in the multiplexing unit 20 shown in FIG. The prism mirrors 31R and 31G are obtained by forming a light reflecting surface 32 on a triangular prism. In addition, instead of the dichroic mirror 21B, the cut surface of the triangular prism obtained by dividing the rectangular parallelepiped into four equal parts reflects the red light reflecting surface 32R that reflects only red light and transmits other light, and reflects only green light and others. A cross dichroic mirror 31B formed so as to be orthogonal to the green light reflecting surface 32G through which the light is transmitted is held at the center.

  In addition, a light shielding wall 36 is provided at the upper portion of the multiplexing unit 30, and an aperture 35 having the same diameter is provided at the center position instead of the aperture 25 of FIG. 1.

  Others are the same as those of the multiplexing unit 20 shown in FIG. For example, the mirror holder 23 is provided with an aperture 34 similar to the aperture 24 at a position where light enters from the light collecting unit 10.

  In the light source device shown in FIG. 7, when driving power is supplied to the red light emitting element 2R, the blue light emitting element 2B, and the green light emitting element 2G through the external terminal 8, R (red) and G (green), respectively. ) And B (blue). The light from each light emitting element is changed in its path by the spherical lens 11 disposed so as to face the light emitting element, and is sorted by the aperture 34 to become a parallel light flux having a beam diameter of 0.4 to 0.5 mm. It enters 31G or the cross dichroic mirror 31B.

  The red light from the red light emitting element 2R is reflected in the horizontal direction by the prism mirror 31R, and subsequently reflected vertically upward by the red light reflecting surface 32R of the cross dichroic mirror 31B. Similarly, the green light from the green light emitting element 2G is reflected in the horizontal direction by the prism mirror 31G, and subsequently reflected vertically upward by the green light reflecting surface 32G of the cross dichroic mirror 31B. The blue light from the blue light emitting element 2R is transmitted vertically through the red light reflecting surface 32R and the green light reflecting surface 32G of the cross dichroic mirror 31B.

  In this way, the three primary color lights of red, green and blue are guided on the same optical axis, and a beam of combined light is formed in the vicinity of the emission side aperture 35 by the overlap of the three primary color lights. Among these, a light beam close to the optical axis and particularly excellent in parallelism is selected by the aperture 35, and is extracted as a parallel light flux having a beam diameter of 10 to 20 μm, for example.

  Similar to the first embodiment, the emitted combined light beam is a high-quality light obtained by selecting light with excellent parallelism near the optical axis. Further, since the light emitted from the light emitting element 2 is converted into a parallel light flux by the spherical lens 11 before spreading, the light density of the combined light beam is high. Such a light source structure is suitable for increasing the amount of light emitted from a light source that emits light having a very small beam diameter, and the characteristics of the emitted light are suitable for application to a retina display or the like.

  Since the other points are the same as those of the first embodiment, it is needless to say that the same effects as those of the first embodiment can be obtained.

  That is, when a chip-like light emitting element with an exposed light emitting portion is used, not only the light emitting element itself can be miniaturized, but also the multiplexing means can be miniaturized and the entire light source device can be miniaturized. When the light source device is downsized, the weight of the light source device is reduced as a result. In addition, since the light emitted from the light emitting element can be used efficiently, power consumed for light emission can be suppressed.

  Further, by using a spherical lens that does not require optical axis adjustment as a condensing lens, a mechanism and adjustment space necessary for optical adjustment are not required, and the light source device can be further downsized. In addition, the condensing lens can be easily disposed within a close distance of the light emitting portion of the light emitting element.

  The accuracy of the sphericity and outer dimensions of the spherical lens 11 is managed to be high, and the center position of the fitting hole 14 provided in the lens stopper 13 and the precision of the dimensions are managed to be high, so that the trouble of performing optical adjustment is reduced. The ball lens 11 can be accurately positioned without applying. Since the above management is relatively easy, it is possible to manufacture a light source device with a high yield, a low efficiency, and a low cost.

Embodiment 3
The combined light beams emitted from the light source devices of Embodiments 1 and 2 described above are high-quality light with excellent parallelism and high light density. The present embodiment is an example in which such a light source device is applied to a micro display such as a retina display.

  FIG. 8 is an explanatory diagram showing a configuration of a head mounted display (HMD) based on the third embodiment of the present invention. In the head mounted display 50, the emitted light 41 emitted from the light source device 40 shown in FIG. 1 forms unit pixels on the retina 45. At this time, the driving power supplied to each light emitting element corresponding to the video signal is controlled by the driving power control device 51, whereby the light emission amounts of the red light emitting element 2R, the blue light emitting element 2B, and the green light emitting element 2G are controlled. The unit pixel can be adjusted to display full color by mixing the three primary color lights.

  The light 41 emitted from the light source device 40 passes through the scanning means 42 and then passes through the retina 45 of the user's eyeball 44 optically conjugate with the scanning means 42 by the lens 43 of the imaging optical system. An image forming point (spot) is connected to the top. This imaging point is scanned two-dimensionally on the retina 45 by the movement of the scanning means 42 synchronized with the video signal, and forms a raster image on the retina 45. The user can perceive the raster image and personally experience a realistic video.

  It should be noted that the head mounted display 50 can be provided with a compact video device by being incorporated in a projector, PDA, camera, computer, game machine or the like while wearing like sunglasses.

  As mentioned above, although this invention was demonstrated based on embodiment, it cannot be overemphasized that this invention is not limited to these examples at all, and can be suitably changed in the range which does not deviate from the main point of invention. For example, one or more of the above-described light emitting elements may be arranged (in the case of a monocolor light source), or one or more of the two kinds may be arranged (multicolor light source). in the case of).

  INDUSTRIAL APPLICABILITY The light source device and the display device of the present invention can be applied to providing a display device capable of color display such as a retinal display device that is expected as a display device of a portable electronic device in a small size, a light weight, and a low cost. .

Sectional view (a) of the light source device of the retinal display according to the first embodiment of the present invention as seen from the light emitting side, and sectional view (b) at the position indicated by line 1A-1A in FIG. It is. FIG. 4 is a cross-sectional view (a) illustrating the structure of the light-emitting element portion as viewed from the light emission side, and a cross-sectional view (b) at the position of the line 1A-1A. It is a perspective view which shows the shape of LED, and the state of an electrical connection similarly. FIG. 6 is a cross-sectional view (a) illustrating the structure of the light condensing unit as viewed from the light emission side, and a cross-sectional view (b) at the position of the line 1A-1A. FIG. 6 is a cross-sectional view (a) illustrating the structure of the multiplexing unit as viewed from the light emission side, and a cross-sectional view (b) at the position of the line 1A-1A. FIG. 4 is an explanatory diagram illustrating the configuration of an optical path until light emitted from a green light emitting element 2G is emitted from an aperture 25. Sectional view (a) of the light source device of the retinal display according to the second embodiment of the present invention, as viewed from the light emitting side, and sectional view (b) at the position indicated by the line 7B-7B in FIG. It is. It is explanatory drawing which shows the structure of the head mounted display based on Embodiment 3 of this invention. It is explanatory drawing which shows the structure of the light source part of the retina display apparatus in which the conventional color display is possible.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light emitting element part, 2 ... Chip-shaped light emitting element, 2R ... Chip-shaped red light emitting element,
2B ... chip-like blue light emitting element, 2G ... chip-like green light emitting element,
3 ... sub-board, 4 ... bottom of support, 5 ... side of support, 6, 7 ... land, 8 ... external terminal,
9 ... Wiring, 10 ... Condensing part, 11 ... Ball lens (ball lens), 12 ... Lens holder,
13 ... Lens stopper, 14 ... Fitting hole, 15 ... Optical axis of spherical lens, 16 ... Light shielding wall,
21R, 21B, 21G ... Dichroic mirror, 22R ... Red light reflecting surface,
22B ... Blue light reflecting surface, 22G ... Green light reflecting surface, 23 ... Mirror holder,
24 ... Aperture (incident side), 25 ... Aperture (exit side), 26 ... Light shielding wall,
31R, 31G ... prism mirror, 31B ... cross dichroic mirror,
32R ... Red light reflecting surface, 32G ... Green light reflecting surface, 33 ... Mirror holder,
34 ... Aperture (incident side), 35 ... Aperture (exit side), 36 ... Light shielding wall,
40 ... light source device, 41 ... emitted light, 42 ... scanning means, 43 ... lens for imaging optical system,
44 ... user's eyeball, 45 ... retina, 50 ... head mounted display,
51 ... Driving power modulation device, 61 ... Upper electrode, 62 ... Lower electrode, 63 ... Wiring pattern,
64 ... Anode, 65 ... Cathode, 101R ... Red light emitting element, 101B ... Blue light emitting element,
101G ... green light emitting element, 102 ... condensing lens, 103 ... dichroic mirror,
104 ... light source unit, 105 ... scanning means, 106 ... lens of projection optical system,
107 ... User's eyeball

Claims (12)

  A light source device comprising: a light emitting element with an exposed light emitting part; and a condenser lens disposed in contact with or facing the light emitting part of the light emitting element.   The light source device according to claim 1, further comprising a plurality of the light emitting elements and a multiplexing unit that multiplexes light emitted from the light emitting elements.   The light source device according to claim 2, wherein the plurality of light emitting elements respectively emit light of a plurality of colors.   The light source device according to claim 2, wherein the multiplexing unit is disposed on a light emitting side of the condenser lens.   The light source device according to claim 1, wherein the condenser lens is a spherical lens (ball lens).   The light source device according to claim 2, wherein the multiplexing unit includes an aperture provided on a substantially optical axis of the light collected by the condenser lens.   3. The multiplex unit includes a dichroic mirror or a dichroic prism that reflects only light in a predetermined wavelength range and transmits light in another wavelength range out of the light collected by the condenser lens. The light source device described in 1.   The light source device according to claim 2, wherein an aperture smaller than a diameter of the combined light beam is provided on a substantially optical axis of the combined light beam at a light emission position of the combining unit.   The light source device according to claim 2, wherein light emission amounts of the plurality of light emitting elements are separately controlled.   The light source device according to claim 3, wherein the plurality of light emitting elements are any one of a red light emitting element, a green light emitting element, and a blue light emitting element.   A display device comprising: the light source device according to any one of claims 1 to 10; and a projection unit that projects light from the light source device. 12. A display device according to claim 11, configured as a retinal display device.

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