Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: An objective lens optical system focuses a light beam with a wavelength ?1 on an information recording surface of a first optical recording medium including a transparent substrate with a thickness t1, a light beam with the wavelength ?1 on an information recording surface of a second optical recording medium including a transparent substrate with a thickness t2, and a light beam with a wavelength ?3 on an information recording surface of a third optical recording medium including a transparent substrate with a thickness t3, by using a refraction action. Sectioning the area of the objective lens optical system is applied to a compatible technique for the same wavelengths, and generating an aberration for canceling a chromatic aberration caused by a difference in wavelength ? of the light beam is applied to a compatible technique for different wavelengths.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength &lgr;1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength &lgr;2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength &lgr;1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength &zgr;2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: A liquid crystal projector comprises an illuminating optical system including a light source, a color separating optical system for separating illuminating light rays emitted by the illuminating optical system into light rays of three colors, a projection lens unit comprising a projection lens, a cross dichroic prism disposed near a light receiving end of the projection lens, and a plurality of liquid crystal panels arranged around the cross dichroic prism, and a light source power supply for supplying power to the light source. The projection lens unit, the color separating optical system, the illuminating optical system and the light source power supply are arranged in that order. The liquid crystal projector has an outside size in a horizontal plane of 263 mm by 318 mm or below. The liquid crystal panels have a display screen size of 0.9 in. A cooling fan for cooling the plurality of liquid crystal panels is disposed beside the projection lens.

Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements. The diagonal size of lens cell is set to almost 0.18 inch or less. The total number of lens cells is set to almost 240 or more. Finally, the lens focal distance of lens cell is set to almost 30 mm or less.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength &lgr;1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength &lgr;2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.