Patent Description:
In a 3D projection apparatus using laser light as a light source, the polarization 3D technology is adopted. The main principle is to convert non-polarized light exited from a lens of the projection apparatus into linearly polarized light by using a linear polarization device. The linearly polarized light is sequentially converted into left-handed circularly polarized light and right-handed circularly polarized light by using a liquid crystal phase modulation device according to a frame sequence. Based on the types of linear polarization device, the polarization 3D technology can be classified into: single-optical-path 3D, dual-optical-path 3D, and three-optical-path 3D. The dual-optical-path and three-optical-path 3D technologies are the major 3D projection technology types used in theaters due to their higher light efficiency.

However, conventional methods may bring high requirements on the production technology of the projection apparatus, which increases the production and usage costs of the projection apparatus.

<CIT>and <CIT> are directed to projection systems comprising a laser light source. Furthermore, <CIT> discloses a projection apparatus including a polarizer.

The present disclosure provides a 3D apparatus including a light source device, to solve the problem that diffraction fringes are easily generated in a laser 3D projection apparatus.

The present disclosure provides a 3D apparatus, including a projection and a polarizing and splitting device, according to claim <NUM>. The polarizing and splitting device includes a prism unit and a lens assembly, and is configured to convert light emitted from the projection apparatus into polarized light through the prism unit and the lens assembly, and project the polarized light on a screen. The projection apparatus includes a light source device and an opto-mechanical device, wherein the opto-mechanical device includes at least one lens and is configured to receive a homogeneous light from the light source device, process the homogeneous light through the lens, and then output the homogeneous light. The light source device includes a laser generation unit configured to output laser light; a light modification element disposed in a light guide unit or between the light guide unit and a homogenizing unit and configured to cause an angular distribution of the laser light uniform and continuous; the light guide unit, configured to receive the laser light output by the laser generation unit and guide the laser light to the homogenizing unit; and the homogenizing unit, configured to receive the laser light from the light guide unit, and homogenize and output the laser light. The prism unit is formed by three or four prisms spliced together and therefore forms a prism seam located on the optical axis of the light emitted from the projection apparatus.

The present disclosure has the following beneficial effects: a light source device includes a laser generation unit, a light modification element, a light guide unit, and a homogenizing unit. The light modification element has the effects of reducing the spatial coherence of the laser light and making an angular distribution of the laser light uniform and continuous. Therefore, by changing the position of the light modification element inside the light source device, the diffraction phenomenon produced by the laser light at the prism seam of the polarizing and splitting prism in the 3D apparatus is weakened, which greatly improves the viewing effect for users.

The present disclosure will be described in detail below in conjunction with the accompanying drawings and embodiments.

<FIG> is a schematic structural diagram of a diffraction principle of a 3D projection technology. Since laser light is a coherent light source with good coherence, the laser light may have a diffraction phenomenon at a prism seam of a polarizing and splitting prism in a 3D projection apparatus. The polarizing and splitting prism in the 3D projection apparatus is formed by three or four prisms spliced together, and therefore, a prism seam will be formed on the optical axis. Depending on the accuracy of the production process, the prism seam may cause the diffraction effect of incident laser light, resulting in horizontal color fringes in the middle of the screen. Laser light emitted from the light source is further homogenized by a light bar of the projection apparatus, but the continuity of laser angular distribution per unit area is not significantly improved. The angular distribution of the beam is no longer changed by the relay lens, prism, digital mirror device (DMD), lens, or the like on the optical path of the projection apparatus. Therefore, light emitted from the lens is light with a discontinuous angular distribution at a light output end of the light bar of the projection apparatus.

<FIG> is a schematic diagram of a diffraction effect of a 3D projection technology. When a 3D movie is played, only a small part in the middle of the whole beam is illuminated on the diffraction obstacle (prism seam) of the three-optical-path 3D projection apparatus, thus forming clear diffraction fringes on the screen to affect the projection viewing effect. At present, the intensity of color fringes can be reduced by special treatment on the prism edge and optimization of the prism gluing and splicing process. This method may bring high requirements on the production technology of the projection apparatus, which increases the production and usage costs of the projection apparatus.

<FIG> is a schematic structural diagram of a light source device according to the present disclosure. The light source device includes a laser generation unit <NUM>, configured to output laser light; a light modification element <NUM>, configured to cause an angular distribution of the laser light uniform and continuous; a light guide unit <NUM>, configured to receive the laser light output by the laser generation unit and guide the laser light to a homogenizing unit; and the homogenizing unit <NUM>, configured to receive the laser light from the light guide unit <NUM>, and homogenize and output the laser light.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. The laser generation unit <NUM> includes a plurality of primary color lasers <NUM>. The primary color lasers <NUM> include a red laser for emitting red laser light, a green laser for emitting green laser light, and a blue laser for emitting blue laser. Laser light emitted from the plurality of primary color lasers is combined by a light combining lens <NUM> and then output to the light guide unit <NUM>. The light guide unit <NUM> includes a first focusing lens <NUM>, a scattering wheel <NUM>, a first relay lens <NUM>, a second relay lens <NUM>, a light guide element <NUM>, a third relay lens <NUM>, and a fourth relay lens <NUM>. The light modification element <NUM> is disposed between the third relay lens <NUM> and the fourth relay lens <NUM>. The first focusing lens <NUM> is configured to gather the laser light guided from the light combining lens <NUM>. Light scattered by the scattering wheel <NUM> sequentially passes through the first relay lens <NUM>, the second relay lens <NUM>, the light guide element <NUM>, the third relay lens <NUM>, the light modification element <NUM>, and the fourth relay lens <NUM>, then enters the homogenizing unit <NUM> through a light incident surface of the homogenizing unit <NUM>, and is output after being homogenized.

In this embodiment, the light modification element <NUM> is a scattering sheet <NUM>, and the homogenizing unit <NUM> is a light bar <NUM>. In other embodiments, the light modification element <NUM> may also be other types of elements, such as a fly-eye lens assembly <NUM>, which is not specifically limited herein, as long as it can modify the optical angle of the laser light to make the angular distribution uniform and continuous.

The laser light emitted from the third relay lens <NUM> has a continuous planar distribution, while the angular distribution is non-uniform and discontinuous. The beam is incident on the scattering sheet <NUM>, and is output after the angle of the beam is expanded by the scattering sheet <NUM>. The scattering sheet <NUM> mainly achieves the effect of improving the angular distribution of the laser. When each scattered beam is gathered by the fourth relay lens <NUM> and then enters the light bar <NUM>, the small beams which are originally separated from each other spatially intersect each other because the divergence angles thereof are expanded by the scattering sheet <NUM>. Each laser light generates a relatively large light spot on an entry surface of the light bar <NUM>, and the light spots overlap with each other, so that each point on the entry surface of the light bar <NUM> receives light from a larger angle range compared with the case without the scattering sheet <NUM>. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. Since the light bar <NUM> homogenizes the beam without changing the angle of the beam, light emitted from each point on an exit surface of the light bar <NUM> also has a larger angle as compared with the case without the scattering sheet <NUM>. Therefore, when the laser light passes through the opto-mechanical device, there will be more light at different angles irradiated on a seam formed between prisms of the polarizing and splitting device <NUM>. After beams at different incident angles pass through the prism seam <NUM>, generated diffraction fringes spatially overlap with each other, so that the overall resolution of the fringes on a screen <NUM> is reduced. By adjusting the scattering angle and scattering form of the scattering sheet <NUM>, the resolution of the fringes can be reduced to a level that is unrecognizable to human eyes.

This embodiment can use a hybrid light source consisting of the laser generation unit <NUM> and an LED light source. The embodiments below are also applicable to the hybrid light source consisting of the laser generation unit <NUM> and the LED light source. Details are not repeated herein.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. The light source device in this embodiment is different from the Embodiment <NUM> in further including a fluorescence generation unit. The fluorescence generation unit includes a laser <NUM> configured to generate laser light to excite fluorescence, a dichroic filter <NUM>, a fluorescent wheel <NUM>, a collection lens assembly <NUM>, and a second focusing lens <NUM>. The dichroic filter <NUM> reflects laser light to be irradiated on the fluorescent wheel <NUM>. The fluorescent wheel <NUM> absorbs the laser light and generates fluorescence, which is transferred through the collection lens assembly <NUM>, the dichroic filter <NUM>, and the second focusing lens <NUM> to the light guide element <NUM>, passes through the light guide element <NUM>, and is combined with laser light to output a hybrid beam. A scattering sheet <NUM> with a particular angle is disposed between the third relay lens <NUM> and the fourth relay lens <NUM> of the light guide unit <NUM>. In the hybrid beam emitted from the light guide element <NUM>, the laser light has a continuous planar distribution but a discontinuous angular distribution. The hybrid beam is incident on the scattering sheet <NUM> through the third relay lens <NUM>, and is output after the angle is expanded by the scattering sheet <NUM>. The scattering sheet <NUM> mainly achieves an effect of improving the angular distribution of the laser light, while hardly changing an angular distribution of the fluorescence. When the laser light in each scattered hybrid beam is gathered by the fourth relay lens <NUM> and then enters the light bar <NUM>, the laser light in the small hybrid beams which are originally separated from each other spatially intersect each other since the divergence angles are expanded by the scattering sheet <NUM>. Each laser light generates a relatively large light spot on an entry surface of the light bar <NUM>, and the light spots overlap with each other, so that each point on the entry surface of the light bar <NUM> receives light from a larger angle range compared with the case without the scattering sheet <NUM>. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. Since the light bar <NUM> homogenizes the beam without changing the angle of the beam, light emitted from each point on a light output end of the light bar <NUM> also has a larger angle as compared with the case without the scattering sheet <NUM>. Therefore, when the laser light passes through the opto-mechanical device <NUM>, there will be more light at different angles irradiated on a seam formed between prisms of the polarizing and splitting device <NUM>. After beams at different incident angles pass through the prism seam <NUM>, generated diffraction fringes spatially overlap with each other, so that the overall resolution of the fringes on the screen <NUM> is reduced. By adjusting the scattering angle and scattering form of the scattering sheet <NUM>, the resolution of the fringes can be reduced to a level that is unrecognizable to human eyes.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. This embodiment is different from Embodiment <NUM> in that, a fly-eye lens assembly <NUM> is used in this embodiment to replace the scattering sheet <NUM>. Both the fly-eye lens assembly <NUM> and the scattering sheet <NUM> have the effect of widening the angle of emission of the fine beam. The first row of lenses in the first row in the fly-eye lens assembly <NUM> splits the entire hybrid beam into multiple fine beams, the second row of lenses located at the focal point of the first row of lenses images each fine hybrid beam in the same area, and the hybrid beams are superimposed on each other to improve the uniformity of the laser light angle.

All laser light in the hybrid beam emitted from the light guide element <NUM> will be completely imaged on the light bar <NUM> after passing through the fly-eye lens assembly <NUM> and the fourth relay lens <NUM>. That is, each small region on the light bar <NUM> will receive a small part of the laser light in the whole hybrid beam. The fly-eye lens assembly <NUM> achieves the same effect as the scattering sheet <NUM> in Embodiment <NUM>, and reduces the spatial coherence of laser. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. Light emitted from each point at a light output end of the light bar <NUM> also has a larger angle as compared with the case without the fly-eye lens assembly <NUM>. Therefore, after the laser light passes through the opto-mechanical device <NUM>, light from more different angles will be irradiated on the seam formed between the prisms of the polarizing and splitting device <NUM>. After beams at different incident angles pass through the prism seam <NUM>, generated diffraction fringes spatially overlap with each other, so that the overall resolution of fringes on the screen <NUM> is reduced. The positions and optical parameters of the fly-eye lens assembly <NUM> and the fourth relay lens <NUM> are adjusted, so that focal spots fill the light incident end of the light bar <NUM> as much as possible, thereby obtaining an optimal diffraction fringe elimination effect. Moreover, in Embodiment <NUM>, a light modification element <NUM> may also be added in front of the light bar <NUM>. The light modification element <NUM> herein may be a fly-eye lens assembly <NUM> or a scattering sheet <NUM>, to further improve the angular distribution of the laser light, expand the angle of the laser light, and enhance the homogenizing effect of the light bar <NUM>, thereby weakening the diffraction fringe phenomenon of the laser light on the screen <NUM>.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. This embodiment is different from Embodiment <NUM> in that, the fly-eye lens assembly <NUM> is located between the first relay lens <NUM> and the second relay lens <NUM>. The diffusion wheel <NUM> and the first focusing lens <NUM> are omitted. The first relay lens <NUM>, which is originally an aspheric lens, is replaced by a spherical lens with a small curvature to collimate pure laser light, thereby reducing the manufacturing costs and difficulty of the light source. In other words, the fly-eye lens assembly <NUM> is moved to a pure laser optical path, so that the fly-eye lens assembly <NUM> in the light guide unit <NUM> only improves the angular distribution of pure laser light that generates diffraction fringes, thereby avoiding influence on fluorescence, and the efficiency of the fluorescence entering the light bar <NUM> is not affected during diffraction fringe elimination. The fly-eye lens assembly <NUM> in Embodiment <NUM> achieves the same effect as the fly-eye lens assembly <NUM> in Embodiment <NUM>, and reduces the spatial coherence of laser light. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. Light emitted from each point at a light output end of the light bar <NUM> also has a larger angle as compared with the case without the fly-eye lens assembly <NUM>. Therefore, after the laser light passes through the opto-mechanical device <NUM>, light from more different angles will be irradiated on the seam formed between the prisms of the polarizing and splitting device <NUM>. After beams at different incident angles pass through the prism seam <NUM>, generated diffraction fringes spatially overlap with each other, so that the overall resolution of fringes on the screen <NUM> is reduced. The positions and optical parameters of the fly-eye lens assembly <NUM> and the second relay lens <NUM> are adjusted, so that focal spots fill the entry of the light bar <NUM> as much as possible, thereby obtaining an optimal diffraction fringe elimination effect.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. This embodiment is different from Embodiment <NUM> in that, on the basis of Embodiment <NUM>, a scattering sheet <NUM> is disposed in front of the light bar <NUM> of the homogenizing unit <NUM>. Such an arrangement alleviates the problem that the laser light from the laser generation unit <NUM> is only homogenized by the fly-eye lens assembly <NUM> and has a poor angular distribution. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. By adding the scattering sheet <NUM> in front of the light bar <NUM>, the angular distribution of the laser light is further improved, the angle of the laser light is expanded, and the homogenizing effect of the projection apparatus light bar <NUM> is enhanced, thereby weakening the diffraction fringe phenomenon of the laser light on the screen <NUM>.

<FIG> is a schematic structural diagram of Embodiment <NUM> of a light source device according to the present disclosure. <FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. The laser generation unit <NUM> in this embodiment includes a plurality of primary color lasers <NUM>. The primary color lasers <NUM> include a red laser for emitting red laser light and a blue laser for emitting blue laser light. Laser light emitted from the plurality of primary color lasers is combined by the light combining lens <NUM> and then transmitted to the light guide unit <NUM>. The light guide unit <NUM> includes a first focusing lens <NUM>, a light guide element <NUM>, a second focusing lens <NUM>, and a collection lens assembly <NUM>. The fluorescence generation unit includes a fluorescent wheel <NUM> and a collection lens assembly <NUM>. The light guide unit <NUM> transfers the hybrid beam to the homogenizing unit <NUM>. In this case, the laser generation unit <NUM> not only generates laser light for the laser generation unit but also generates laser light for the fluorescence generation unit.

In this embodiment, the light modification element <NUM> is a scattering sheet diffuse reflective sheet <NUM>, which is disposed on a light propagation path of the collection lens assembly <NUM> of the light guide unit <NUM>. The homogenizing unit <NUM> is a light bar <NUM>. The light guide element <NUM> is a regional film.

Laser light emitted from the primary color lasers <NUM> is gathered by the light combining lens <NUM> and the first focusing lens <NUM>, and then transmitted to the light guide element <NUM> formed by the regional film. A central region of the regional film allows one type of laser light to pass and reflects another type of laser light. For example, the central region allows blue laser light to pass and reflects red laser light. A peripheral region reflects blue laser light and allows yellow fluorescence to pass. Laser light reflected by the regional film is transferred to the fluorescent wheel <NUM>. The entire phosphor section on the fluorescent wheel <NUM> is a yellow phosphor section. Therefore, fluorescence generated by the fluorescent wheel <NUM> is yellow fluorescence, so that the yellow fluorescence passes through the peripheral region of the regional film. Red laser light is guided to the yellow phosphor section through the regional film. The wavelength of the red laser light is not converted, but the laser light will be dispersed, and the angular distribution will become continuous. Therefore, the red laser light will also pass through the peripheral region of the regional film. Laser light passing through the center of the regional film is transmitted to the diffuse reflective sheet <NUM> through the collection lens assembly <NUM>. The scattering sheet <NUM> and the fly-eye lens assembly <NUM>, the diffuse reflective sheet <NUM> can also achieve the effects of expanding the angle of the laser light and reducing the spatial coherence. Laser light reflected by the diffuse reflective sheet <NUM> is transmitted through the collection lens assembly <NUM> again to the regional film, to be combined with the fluorescence to form a hybrid beam, which is transferred to the second focusing lens <NUM> and transmitted to the light incident end of the light bar <NUM>. <FIG> is a schematic diagram of a principle of eliminating diffraction fringes according to the present disclosure. Light emitted from each point at the light output end of the light bar <NUM> has a larger angle. Therefore, after the laser light passes through the opto-mechanical device <NUM>, light from more different angles will be irradiated on the seam <NUM> formed between the prisms of the polarizing and splitting device <NUM>. After beams at different incident angles pass through the prism seam <NUM>, generated diffraction fringes spatially overlap with each other, so that the overall resolution of fringes on the screen <NUM> is reduced. The positions and optical parameters of the diffuse reflective sheet <NUM> and the light guide element <NUM> are adjusted, so that focal spots fill the entry of the light bar <NUM> as much as possible, thereby obtaining an optimal diffraction fringe elimination effect.

In any of the foregoing embodiments, the element type and arrangement position of the light modification element <NUM> can be selected according to specific requirements, and are not limited to the situation described in the embodiments of the present disclosure.

<FIG> is a schematic structural diagram of a projection apparatus according to the present disclosure. The projection apparatus includes a light source device described in any of the foregoing embodiments, and an opto-mechanical device <NUM>. The opto-mechanical device <NUM> includes at least one lens and is configured to receive a homogeneous light from the light source device, process the homogeneous light through the lens, and then output the beam. Other components and functions of the opto-mechanical device <NUM> and the projection apparatus are the same as those in the related art, and details are not described herein again.

<FIG> is a schematic structural diagram of a 3D apparatus according to the present disclosure. The 3D apparatus includes the projection apparatus described above and a polarizing and splitting device <NUM>. The polarizing and splitting device <NUM> includes a prism unit and a lens assembly, and is configured to convert a beam emitted from the projection apparatus into polarized light through the prism unit and the lens assembly, and project the polarized light on a screen. Other components and functions of the polarizing and splitting device <NUM> and the 3D apparatus are the same as those in the related art, and details are not described herein again.

In the present disclosure, the light modification element has the effects of reducing the spatial coherence of the laser light and making an angular distribution of the laser light uniform and continuous, so that the diffraction phenomenon produced by the laser light, which is emitted from the light source device, irradiated on the prism seam of the polarizing and splitting prism in the 3D apparatus is weakened, which greatly improves the viewing effect for users.

Claim 1:
A 3D projection apparatus, comprising a projection apparatus and a polarizing and splitting device (<NUM>), wherein the projection apparatus comprises a light source device and an opto-mechanical device (<NUM>), the light source device comprising:
a laser generation unit (<NUM>) configured to output laser light;
a light modification element (<NUM>);
a light guide unit (<NUM>), configured to receive the laser light output by the laser generation unit (<NUM>) and guide the laser light to a homogenizing unit (<NUM>); and
the homogenizing unit (<NUM>), configured to receive the laser light from the light guide unit (<NUM>), and homogenize and output the laser light,
wherein the opto-mechanical device (<NUM>) comprises at least one lens and is configured to receive homogeneous light from the light source device, process the homogeneous light through the lens, and then output the homogeneous light,
wherein the polarizing and splitting device (<NUM>) comprises a prism unit and a lens assembly, and is configured to convert light emitted from the projection apparatus into polarized light through the prism unit and the lens assembly, and project the polarized light on a screen (<NUM>), and
characterized in that
the prism unit is formed by three or four prisms spliced together and therefore forms a prism seam (<NUM>) located on the optical axis of the light emitted from the projection apparatus, and
the light modification element (<NUM>) is disposed in the light guide unit (<NUM>) or between the light guide unit (<NUM>) and a homogenizing unit (<NUM>) and is configured to cause an angular distribution of the laser light uniform and continuous and to weaken the diffraction phenomenon produced by the laser at the prism seam (<NUM>) of the polarizing and splitting device (<NUM>).