Optical system, image projection apparatus including the same and an image pickup device
AssigneeKonica Minolta Opto, Inc.
InventorMasayuki IMAOKA
Life of this patent
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Abstract
Provided is an optical system (PS) which is used in a wavelength range including a near ultraviolet light range having a wavelength longer than approximately 350 nm and a visible light range. The optical system includes at least two first positive lenses which satisfies a predetermined conditional expression concerning anomalous dispersion characteristic and a rate of change of the refractive index with respect to temperature, and is disposed closer to a contraction side than an aperture stop (ST), and at least one second positive lens which satisfies a predetermined conditional expression concerning anomalous dispersion characteristic and a rate of change of the refractive index with respect to temperature.
Claims21
An optical system which is used in a wavelength range including a near ultraviolet light range having a wavelength longer than approximately 350 nm and a visible light range, comprising:
- at least two first positive lenses satisfying the following conditional expressions (1) to (3) disposed closer to a contraction side than an aperture stop;
- and
- at least one second positive lens satisfying the following conditional expressions (1), (4) and (5):
- 60<Vd (1)
- 0.67<0.0018Vd+P (2)
- −7.5×10−6<dN/dT<−0.5×10−6 (3)
- 0.645<0.0018Vd+P (4)
- 9×10−6<dN/dT (5)
- where, Vd denotes an Abbe number at the d-line, P=(Ng−NF)/(NF−NC), Ng denotes a refractive index at the g-line, NF denotes a refractive index at the F-line, NC denotes a refractive index at the C-line, and dN/dT denotes a rate of change of the refractive index with respect to temperature in the vicinity of room temperature.
An image projection apparatus comprising:
- an optical modulation element which modulates light in accordance with image data;
- an illumination optical system which leads the light to the optical modulation element;
- and
- an optical system which leads the light modulated by the optical modulation element to a projection surface, the optical system including
- at least two first positive lenses which satisfy the following conditional expressions (1) to (3) and are disposed closer to a contraction side than an aperture stop, and
- at least one second positive lens which satisfies the following conditional expressions (1), (4) and (5):
- 60<Vd (1)
- 0.67<0.0018Vd+P (2)
- −7.5×10−6<dN/dT<−0.5×10−6 (3)
- 0.645<0.0018Vd+P (4)
- 9×10−6<dN/dT (5)
- where, Vd denotes an Abbe number at the d-line, P=(Ng−NF)/(NF−NC), Ng denotes a refractive index at the g-line, NF denotes a refractive index at the F-line, NC denotes a refractive index at the C-line, and dN/dT denotes a rate of change of the refractive index with respect to temperature in the vicinity of room temperature.
An image pickup device comprising:
- an optical system through which light enters from an object;
- and
- an image pickup element which receives the light from the optical system, wherein
- the optical system including
- at least two first positive lenses which satisfy the following conditional expressions (1) to (3) and are disposed closer to a contraction side than an aperture stop, and
- at least one second positive lens which satisfies the following conditional expressions (1), (4) and (5):
- 60<Vd (1)
- 0.67<0.0018Vd+P (2)
- −7.5×10−6<dN/dT<−0.5×10−6 (3)
- 0.645<0.0018Vd+P (4)
- 9×10−6<dN/dT (5)
- where, Vd denotes an Abbe number at the d-line, P=(Ng−NF)/(NF−NC), Ng denotes a refractive index at the g-line, NF denotes a refractive index at the F-line, NC denotes a refractive index at the C-line, and dN/dT denotes a rate of change of the refractive index with respect to temperature in the vicinity of room temperature.
Dependencies are inferred from the claim text.