Image display device which reduces mutual interference of light reflected by a screen
View Patent ↗An image display device which reduces speckles in an image display device using a laser source includes: a laser source which emits excitation light; a collecting lens which collects the excitation light; a deflecting element which scans the excitation light collected by the collecting lens; and a light conversion panel which converts a wavelength of the excitation light scanned by the deflecting element and emits fluorescence, wherein the light conversion panel includes a plurality of phosphor layers which are planarly disposed, absorb the excitation light, and emit the fluorescence.
1. An image display device comprising:
a laser source which emits laser light having a single center wavelength;
a collecting lens which is disposed on a light-emission side of the laser source and collects the laser light;
a deflecting element which is disposed on a light-collection side of the collecting lens and scans the laser light;
a light conversion panel which receives the laser light scanned, converts a wavelength of the laser light, and emits multi-colored fluorescence; and
a projector lens which projects the light emitted from the light conversion panel,
wherein the light conversion panel includes a plurality of phosphor layers which are planarly disposed, absorb the laser light having the single center wavelength, and emit the multi-colored fluorescence,
wherein the light conversion panel includes a first optical element which guides the laser light to the phosphor layers,
wherein the light conversion panel includes a second optical element which transmits the fluorescence,
wherein the light conversion panel further includes a transparent substrate which is disposed between the phosphor layers and the first optical element and transmits the laser light, and
the first optical element is a first microlens array and the second optical element is a second microlens array, and
the phosphor layers including a red layer, a green layer, and a blue layer,
the red layer absorbs the laser light and emits red light, the green layer absorbs the laser light and emits green light, and the blue layer absorbs the laser light and emits blue light,
the red layer, the green layer, and the blue layer are each linearly disposed,
the first microlens array including a plurality of microlenses formed in dots,
the second microlens array including a plurality of microlenses formed in dots,
the microlenses included in the first microlens array and the microlenses included in the second microlens array are disposed on a plane in correspondence with the lines of the phosphor layers,
three microlenses included in the first microlens array and three microlenses included in the second microlens array disposed in a direction perpendicular to the straight lines correspond to three colors and make up a full-colored unit pixel.
2. The image display device according to claim 1 , wherein the light conversion panel includes a spacer between the phosphor layers, the spacer including a high thermal conducting material having a thermal conductivity higher than a thermal conductivity of the phosphor layers.
3. The image display device according to claim 2 , wherein the high thermal conducting material includes at least one of zinc oxide, aluminum nitride, and diamond.
4. The image display device according to claim 1 , wherein the light conversion panel includes a spacer between the phosphor layers, the spacer including a highly reflective material having a reflectance higher than a reflectance of the phosphor layers.
5. The image display device according to claim 1 , wherein the phosphor layers are linearly disposed.
6. The image display device according to claim 1 , comprising an imaging lens which forms an image using the fluorescence emitted from the phosphor layers.
7. The image display device according to claim 1 ,
wherein the laser source emits laser light having the wavelength in a range from 350 nm to 430 nm, and
the red layer is a phosphor layer which emits red light, the green layer is a phosphor layer which emits green light, and the blue layer is a phosphor layer which emits blue light.
8. The image display device according to claim 1 ,
wherein the laser source emits laser light having the wavelength in a range from 430 nm to 500 nm, and
the red layer is a phosphor layer which emits red light, the green layer is a phosphor layer which emits green light, and the blue layer is a diffusion layer which diffuses the laser light.
9. The image display device according to claim 1 , wherein the red layer, the green layer and the blue layer are disposed in parallel straight lines in positions corresponding to microlenses of second microlens array, and the red layer, the green layer and the blue layer are formed in elliptical or circular shapes.
10. An image display device comprising:
a laser source which emits laser light having a single center wavelength;
a collecting lens which is disposed on a light-emission side of the laser source and collects the laser light;
a deflecting element which is disposed on a light-collection side of the collecting lens and scans the laser light;
a light conversion panel which receives the laser light scanned, converts a wavelength of the laser light, and emits multi-colored fluorescence;
a projector lens which projects the light emitted from the light conversion panel; and
a dichroic mirror which transmits the laser light and reflects the fluorescence,
wherein the light conversion panel includes a plurality of phosphor layers which are planarly disposed, absorb the laser light having the single center wavelength, and emit the multi-colored fluorescence,
wherein the light conversion panel includes an optical element which guides the laser light to the phosphor layers,
wherein the light conversion panel further includes a transparent substrate which is disposed between the phosphor layers and the optical element and transmits the laser light, and
the optical element is a microlens array, and
the phosphor layers including a red layer, a green layer, and a blue layer,
the red layer absorbs the laser light and emits red light, the green layer absorbs the laser light and emits green light, and the blue layer absorbs the laser light and emits blue light,
the red layer, the green layer, and the blue layer are each linearly disposed,
the microlens array including a plurality of microlenses formed in dots,
the microlenses included in the microlens array is disposed on a plane in correspondence with the lines of the phosphor layers,
three microlenses included in the microlens array disposed in a direction perpendicular to the straight lines correspond to three colors and make up a full-colored unit pixel,
wherein the dichroic mirror is tilted to a surface of the light conversion panel, the surface is arranged by the microlens array,
the light conversion panel further includes a reflecting layer which reflects the fluorescence emitted from the phosphor layers,
wherein the laser light scanned by the deflecting element passes through the dichroic mirror and enters the light conversion panel,
the laser light which enters the light conversion panel is collected by the microlens array and enters to the phosphor layers,
the fluorescence from the phosphor layers is reflected off the reflecting layer passes through the phosphor layers and the microlens array and emitted from the light conversion panel,
the fluorescence which has emitted from the light conversion panel is reflected off the dichroic mirror and enters to the projector lens.