Source: https://patents.google.com/patent/JP2010014815A/en
Timestamp: 2020-01-17 22:39:06
Document Index: 180949245

Matched Legal Cases: ['art 36', 'art 361', 'art 361', 'art 36', 'art 361', 'art 36', 'art 20', 'art 34', 'art 37', 'art 362']

JP2010014815A - Projection type display device - Google Patents
JP2010014815A
JP2010014815A JP2008172633A JP2008172633A JP2010014815A JP 2010014815 A JP2010014815 A JP 2010014815A JP 2008172633 A JP2008172633 A JP 2008172633A JP 2008172633 A JP2008172633 A JP 2008172633A JP 2010014815 A JP2010014815 A JP 2010014815A
JP2008172633A
Shinji Yagyu
伸二 柳生
2008-07-01 Application filed by Mitsubishi Electric Corp, 三菱電機株式会社 filed Critical Mitsubishi Electric Corp
2008-07-01 Priority to JP2008172633A priority Critical patent/JP2010014815A/en
2010-01-21 Publication of JP2010014815A publication Critical patent/JP2010014815A/en
<P>PROBLEM TO BE SOLVED: To provide a projection type display device using a laser light source, reducing the overall thickness of the device and eliminating annular color unevenness which is highly likely to occur when viewing a 3D video image using a liquid crystal shutter system. <P>SOLUTION: In this projection type display device 1, an image is formed by an optical engine 30 using a laser beam from a laser light source 10, and the laser beam emitted from the optical engine 30 is enlarged and displayed on a screen 51. The laser light source 10 and the optical engine 30 are connected to each other by an optical fiber 20. The optical engine 30 includes a rod fiber fixing part 36 disposed in the optical engine 30, wherein the rod integrator 31 and the optical fiber 20 are disposed so that an incident end face of the rod integrator 31 for making uniform the distribution of quantity of laser beams from the laser light source 10 faces an exit end face of the optical fiber 20 with a space larger as compared with the wavelength of light propagated by the optical fiber 20, and fixed by the rod fiber fixing part. <P>COPYRIGHT: (C)2010,JPO&INPIT
The present invention relates to a projection display device that includes a laser light source and an optical fiber and provides a 3D image using a liquid crystal shutter system.
Conventional projection display devices have used incoherent (incoherent) and relatively low-luminance light sources such as mercury lamps and light emitting diodes (LEDs) (for example, see Patent Document 1). On the other hand, since laser light has excellent directivity and high luminance, it is promising as a light source for a projection display device. For this reason, the development of a projection display device equipped with a laser light source, which is an excellent point light source with excellent light condensing performance, and includes an optical engine that is compact and suitable for a thin type has been made (for example, Patent Document 2).
JP 2006-91867 A JP 2000-131665 A
When a light source with excellent light condensing properties such as a laser light source is mounted, the optical system can be made compact, and the projection display device can be easily made thinner as the optical system. On the other hand, when the projection display device becomes thinner, the storage space in the device becomes narrower, and it becomes difficult to install components that need to be stored in the device such as a laser light source, a power supply circuit, and a signal processing circuit. It was a factor that hindered thinning.
In recent years, new demands for enjoying 3D images have been increasing in large-sized projection display devices, particularly TV products in the consumer field. It is well known that various methods for providing 3D video have been proposed, but the most convenient way to achieve this is to enjoy 3D video using liquid crystal shutter glasses. However, in the case of a projection display device equipped with a laser light source, due to the strong polarization property of the laser light source, characteristic ring-shaped color irregularities appear on the screen in combination with liquid crystal shutter glasses, and the quality of the image is remarkably increased. There was a problem of losing.
The present invention has been made in view of the above. In a projection display apparatus using a laser light source, the entire apparatus can be made thin, and can be expressed when enjoying a 3D image using a liquid crystal shutter system. It is an object of the present invention to obtain a projection display device capable of removing highly irregular ring-shaped color unevenness.
In order to achieve the above object, a projection display device according to the present invention forms an image with an optical engine using laser light from a laser light source, and enlarges and displays the laser light emitted from the optical engine on a screen. In the projection display apparatus, the laser light source and the optical engine are connected by an optical fiber, and the optical engine is disposed in the optical engine, and the light quantity distribution of the laser light from the laser light source is made uniform. A rod fiber fixing means for fixing the incident end face of the rod integrator and the outgoing end face of the optical fiber facing each other with a gap larger than the wavelength of light propagated through the optical fiber; It is characterized by that.
According to this invention, an interval larger than the wavelength of the light propagating through the optical fiber is provided between the end surface of the optical fiber that transmits the light from the laser light source and the incident surface of the rod integrator that is connected to the subsequent stage. Since it is provided, there is an effect that characteristic color unevenness caused by a combination of a laser light source having strong polarization and an optical element having a polarization selection function can be reduced.
Exemplary embodiments of a projection display apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.
FIG. 1 is a diagram schematically showing an example of the configuration of a projection display apparatus according to an embodiment of the present invention. The projection display device 1 includes a laser light source 10, an optical fiber 20, an optical engine 30, and an enlarged projection lens 40, and these are arranged in a housing 50. Further, a screen 51 for enlarging and displaying an image from the enlargement projection lens 40 is provided on the surface on the casing 50 facing the enlargement projection lens 40. In the following description, the component arranged on the optical path is referred to as the latter stage if it is arranged far from the light source.
The laser light source 10 includes light source units 11-1, 11-2, and 11-3 corresponding to a plurality of colors of laser light. For example, the light source units 11-1, 11-2, and 11-3 output laser beams of three colors of red, green, and blue.
The optical fiber 20 is formed by bundling a plurality of optical fibers 21-1, 21-2, and 21-3 provided corresponding to the respective light source units 11-1, 11-2, and 11-3 on the way. A bundle is connected to the optical engine 30 at a single exit end. Accordingly, the optical fiber 20 constitutes a laser transmission optical path that propagates the laser light from the laser light source 10 and sends it to the optical engine 30.
The optical engine 30 is arranged at the rear stage of the bundled emission end of the optical fiber 20, a rod integrator 31 that equalizes the light amount distribution, a lens 32 that converges and emits the light emitted from the rod integrator 31, and a lens A light diffusing unit 33 including a rotating optical device that transmits and diffuses the laser light from 32, and a reflection mirror that guides the laser light from the light diffusing unit 33 to the display device 35 and irradiates the display device 35 with the laser light. 34 and a display device 35 which is a reflection type light modulation element such as DMD (Digital Micro-mirror Device). The enlargement projection lens enlarges the laser beam from the display device 35 and projects it onto the screen 51.
In this way, by connecting the laser light source 10 and the optical engine 30 with the optical fiber 20, the degree of freedom of arrangement of components that need to be housed in the apparatus, such as the laser light source 10, power supply circuit, and signal processing circuit, is remarkably improved. In addition, the projection display device 1 can be thinned.
The optical engine 30 uses the rod integrator 31. Since this uses the laser light source 10 as a light source, the rod integrator 31 that can reduce the size of the apparatus due to its high light condensing performance. It is because it is preferable to apply. However, the hollow rod integrator has a problem that it is difficult to efficiently propagate light having a short wavelength due to the characteristics of a metal reflective film such as aluminum or silver formed on the inner surface thereof. In particular, when the F number of the optical system is increased by taking advantage of the condensing property of the laser light, it is necessary to increase the number of reflections on the metal reflecting surface in order to obtain a predetermined uniformity. However, there was a disadvantage in that it was significantly large. Further, when the laser light source 10 is used, unlike a high-pressure mercury lamp or a xenon lamp that has been widely used in the past, ultraviolet light is not generated, and therefore an optical filter provided for removing ultraviolet light has a short wavelength. Light energy, that is, a blue component is not lost, and a deep blue expression that cannot be realized by a conventional projection display device can be obtained. There is a problem in that the inconvenience is further increased because the wavelength range of performance is further expanded to the short wavelength side. Therefore, in this embodiment, a solid rod integrator is used as the rod integrator 31. As a result, as compared with the case where a hollow rod integrator is used, the light loss of the short wavelength as described above is suppressed.
In the projection display device 1 having such a configuration, the laser light emitted from the laser light source 10 passes through the optical fiber 20 that is a laser transmission optical path, and the optical surface of the light diffusion unit 33 installed in the optical engine 30. The image is irradiated on the display device 35 through the image forming apparatus, thereby forming an image. Then, the image is enlarged and projected onto a large screen 51 provided in the housing 50 via the enlargement projection lens 40, and an image is displayed.
FIG. 2 is a diagram showing in more detail how the laser light source and the optical engine are connected by an optical fiber. The light source units 11-1, 11-2, and 11-3 emit light from the emitters 12-1, 12-2, and 12-3 and the emitters 12-1, 12-2, and 12-3 that emit laser beams of the respective colors. Coupling optical systems 13-1, 13-2, and 13-3 that collect and converge the received light are included. Then, the incident end faces of the optical fibers 21-1, 21-2, 21-3 are arranged in the light spot portions 14-1, 14-2, 14-3 so that the light energy is efficiently transmitted. ing.
The laser beams transmitted to the respective optical fibers 21-1, 21-2, and 21-3 through the coupling optical systems 13-1, 13-2, and 13-3 are transmitted by the optical transmission function of the optical fiber 20. It is guided to the optical engine 30 at the subsequent stage. The optical fiber 21-1, 21-2, 21-3 of the optical fiber 21-1, 21-2, 21-3 has an optical fiber 21-from which the plastic clad portion is removed from the incident end by a predetermined dimension 1, 21-2 and 21-3 are inserted, and a metal connector is attached by mechanically clamping the clad layer from the outside at a portion where a clad layer separated by a predetermined distance from the incident end remains.
The optical engine includes a rod fiber fixing portion 36 to which an optical fiber 20 and a solid rod integrator 31 are connected via an air gap 37. Here, the rod fiber fixing portion 36 fixes the optical fiber 20 via a metal bundle portion 361 that bundles a plurality of optical fibers 21-1, 21-2, and 21-3 extending from the laser light source 10 into a rectangular parallelepiped shape. However, the solid rod integrator 31 is directly fixed as it is.
FIG. 3 is a cross-sectional view showing a part of the configuration of the rod fiber fixing portion. In the rod fiber fixing portion 36, at least two substantially rectangular parallelepiped (prism-like) spaces 362 and 363 having different sizes are formed inside, and one of them fixes the rectangular parallelepiped bundle portion 361. The other space 362 is a space 363 for fixing the solid rod integrator 31 having a rectangular parallelepiped shape.
Here, the end surface (light emitting end surface) forming a substantially rectangular shape (rectangular shape) of the bundle portion 361 including the optical fiber 20 is set larger than the end surface (light incident end surface) forming the substantially rectangular shape (rectangular shape) of the solid rod integrator 31. Has been. Further, the bundle unit 361 can use the outer surface of the bundled optical fiber 20 as a position reference surface. Thereby, the relative position of the optical fiber 20 and the solid rod integrator 31 can be determined with high accuracy.
Further, the solid rod integrator 31 is fixed in the space 363 so that the incident end face thereof has a predetermined distance from the outgoing end face of the optical fiber 20, and as a result, the incident end face of the solid rod integrator 31 and the light An air gap 37 is formed in the space between the emission end face of the fiber 20. The air gap 37 is larger than the wavelength of light propagating in the optical fiber 20, and preferably has a sufficiently large interval as compared with the wavelength of light propagating in the optical fiber 20. Specifically, for the convenience of assembly, a distance of 0.1 to 0.2 mm is suitable for management.
Here, the light L that has propagated from the laser light source 10 through the optical fiber 20 travels as indicated by an arrow in FIG. 3, for example, and is emitted from the optical fiber 20 to the solid rod integrator 31 with almost no leakage. It enters and propagates further to the subsequent optical system by the total reflection action of this interface.
The exit end face of the bundle part 361 including the optical fiber 20 can be made to be an end face with high flatness by polishing after the optical fiber 20 is disposed, and the incident end face of the solid rod integrator 31 is also the same. By this method, an end face with high flatness can be obtained. However, if the bundle part 361 and the solid rod integrator 31 are arranged in contact with each other, the two opposing end faces become completely parallel due to the structural reason that both are attached to the rod fiber fixing part 36. Is difficult to arrange. In other words, it is actually difficult to make the external shape requirements such as the perpendicularity of the end face and side face of each part and the parallelism of the side face ideal values, so both end faces are inclined at slightly different angles. It is inevitable that there will be a very small air gap between them. In this case, light interference occurs in a slight air gap, and an annular color unevenness may be visually recognized depending on the combination with other polarizing elements. For example, when enjoying 3D images using polarized glasses (liquid crystal shutter glasses), ring-shaped color irregularities are visually recognized on the screen, and the quality of the images is significantly impaired.
However, in this embodiment, since the air gap 37 is formed with a sufficiently large interval compared to the wavelength of light, the above-described ring-shaped color unevenness can be eliminated. In order to further increase the distance of the air gap 37, it is necessary to increase the relative dimensions of the solid rod integrator 31, which is preferable in terms of light propagation efficiency. Since the margin becomes too large, the optimum air gap 37 distance is determined in consideration of the overall light utilization efficiency. Further, by forming the air gap 37, when assembling the bundle part 361 and the solid rod integrator 31 to the rod fiber fixing part 36, the end face of the optical fiber 20 or the end face of the solid rod integrator 31 is damaged. There is also an advantage that it is easy to avoid the risk of injury.
According to this embodiment, in the optical engine 30, the optical fiber 20 and the solid rod integrator 31 are arranged at a distance that is sufficiently larger than the wavelength of light whose end face propagates through the apparatus. Therefore, the light emitted from the optical fiber 20 does not interfere with the air gap 37 with the solid rod integrator 31. As a result, the ring-shaped color unevenness is prevented from being visually recognized in combination with other polarizing elements. In particular, there is an effect that a high-quality 3D image can be provided through polarized glasses using a liquid crystal shutter system.
Further, since the laser light source 10 is used and the laser light source 10 and the optical engine 30 are connected by the optical fiber 20, the projection display device 1 can be thinned.
As described above, the projection display device according to the present invention is useful for a consumer TV using a high-power laser as a light source, and is particularly suitable for an industrial rear projection device.
It is a figure which shows typically an example of a structure of the projection type display apparatus by embodiment of this invention. It is a figure which shows the mode of the connection by the optical fiber of a laser light source and an optical engine further in detail. It is sectional drawing which shows a part of structure of a rod fiber fixing | fixed part.
DESCRIPTION OF SYMBOLS 1 Projection type display apparatus 10 Laser light source 11-1 to 11-3 Light source unit 12-1 to 12-3 Emitter 13-1 to 13-3 Coupling optical system 14-1 to 14-3 Light spot part 20, 21- 1-21-3 Optical fiber 22-1-22-3 Incident end connector 30 Optical engine 31 Rod integrator 32 Lens 33 Light diffusing part 34 Reflecting mirror 35 Display device 36 Rod fiber fixing part 37 Air gap 40 Enlarged projection lens 50 Housing 51 Screen 361 Bundle part 362, 363 Space
In a projection display device that forms an image with an optical engine using laser light from a laser light source, enlarges the laser light emitted from the optical engine, and displays it on a screen.
An optical fiber is connected between the laser light source and the optical engine,
The optical engine is disposed in the optical engine, and is propagated by the optical fiber through an incident end surface of a rod integrator that uniformizes a light amount distribution of laser light from the laser light source and an output end surface of the optical fiber. A projection-type display device comprising rod fiber fixing means arranged opposite to each other with a gap larger than the wavelength of light.
The projection display device according to claim 1, wherein the rod integrator is solid.
The laser light source comprises a plurality of
The incident end surface of the rod integrator has a rectangular shape,
Bundling means for bundling the plurality of optical fibers connected to the laser light sources so that the emission end face has a rectangular shape on the optical engine side;
3. The projection display device according to claim 1, wherein an area of a rectangular emission end face of the bundle means including the optical fiber is larger than a rectangular incident end face of the rod integrator.
JP2008172633A 2008-07-01 2008-07-01 Projection type display device Pending JP2010014815A (en)
JP2008172633A JP2010014815A (en) 2008-07-01 2008-07-01 Projection type display device
US12/487,996 US8113661B2 (en) 2008-07-01 2009-06-19 Projection-type display apparatus
JP2010014815A true JP2010014815A (en) 2010-01-21
ID=41464101
JP2008172633A Pending JP2010014815A (en) 2008-07-01 2008-07-01 Projection type display device
US (1) US8113661B2 (en)
JP (1) JP2010014815A (en)
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