摘要:
When a projection lens system used for a rear projection type image display apparatus has a first lens group having an aspherical lens surface, a second lens group, a third lens group sharing almost all the positive refractive power of the overall system, a fourth lens group having an aspherical lens surface, a fifth lens group, and a sixth lens group including a lens having a profile of aspherical surface in which the concave surface thereof faces the screen side and the refractive power in the marginal area is weaker than the refractive power around the optical axis, a projection lens system having a large aperture ratio (low F-number), high focus, wide field angle, and sufficient marginal light amount ratio can be realized at a low cost. When a predetermined opening portion is formed in the projection lens and lens barrel, the lens elements are cooled by air suction and exhaust and the lowering of the lens performance due to temperature change can be prevented. When a flange is arranged in a suitable location of the opening portion, entry of a foreign material from the opening portion and light leakage from the inside are prevented and the contrast performance of the projection type image display apparatus can be prevented from lowering.
摘要:
For obtaining both high brightness under condition of small-sized and simplified structure and suppression of increase in temperature of liquid crystal display elements and polarizing elements, in a liquid crystal display apparatus, comprising: a liquid crystal display element 2 for converting light from a light source into display picture depending on a driving signal; an optical projection system 1b containing a first optical element 1a and for projecting said light signal toward an object of projection; exit side polarizing elements 3b; a holding member 6 for holding them with the liquid crystal display element 2; and cooling medium 5; incident side polarizing elements 3a, wherein, a space is defined by either one of the incident side polarizing elements 3a and the liquid crystal display element 2, the first optical element 1a, between the liquid crystal display element 2 and the first optical element 1a, and the holding member 6, and said space is filled up with the cooling medium 5.
摘要:
For providing a rear-projection type display apparatus, and a translucent type sheet for use therein, in particular, using an image modulation element, such as, a liquid crystal or a DMD (Digital Micro-mirror Device), etc., dissolving the speckle disturbances, thereby obtaining a picture being high in brightness and superior in resolution (focus property) thereof, wherein the translucent type screen comprises, a Fresnel sheet (6), at least on a light exit surface of which is formed a Fresnel lens (8), and a lenticular sheet (7), at least on a light incident surface of which is formed a lenticular lens (10) for diverging the light in horizontal direction, and the Fresnel sheet contains light diffusion material (9-1) while the lenticular sheet contains diffusion material (9-2), and being constructed so as to satisfy the condition as described below:15nullHfnullHLnull45Hf
摘要:
An on-line roll grinding apparatus which includes a grinding unit having a rotatable rotary grindstone for on-line grinding a rolling roll and a roughness adjusting unit capable of adjusting A surface roughness of the rolling roll, and which can adjust the surface roughness of the rolling roll in AN on-line roll grinding.
摘要:
A grinding head unit is constituted by a grinding wheel, a drive device for rotating the grinding wheel, and a movement device for moving the grinding wheel. When vibration of a mill roll is applied to the grinding wheel, a plain wheel integral with an abrasive layer of the grinding wheel and having an elastically deforming function is deflected to absorb the vibration energy. The contact force between the abrasive layer and the mill roll is measured for determining a profile of the mill roll. The mill roll can be thereby ground into a target profile while absorbing the vibration transmitted from the mill roll and measuring the profile of the mill roll, without causing any chattering marks.
摘要:
When a projection lens system used for a rear projection type image display apparatus has a first lens group having an aspherical lens surface, a second lens group, a third lens group sharing almost all the positive refractive power of the overall system, a fourth lens group having an aspherical lens surface, a fifth lens group, and a sixth lens group including a lens having a profile of aspherical surface in which the concave surface thereof faces the screen side and the refractive power in the marginal area is weaker than the refractive power around the optical axis, a projection lens system having a large aperture ratio (low F-number), high focus, wide field angle, and sufficient marginal light amount ratio can be realized at a low cost. When a predetermined opening portion is formed in the projection lens and lens barrel, the lens elements are cooled by air suction and exhaust and the lowering of the lens performance due to temperature change can be prevented. When a flange is arranged in a suitable location of the opening portion, entry of a foreign material from the opening portion and light leakage from the inside are prevented and the contrast performance of the projection type image display apparatus can be prevented from lowering.
摘要:
For obtaining both high brightness under condition of small-sized and simplified structure and suppression of increase in temperature of liquid crystal display elements and polarizing elements, in a liquid crystal display apparatus, comprising: a liquid crystal display element 2 for converting light from a light source into display picture depending on a driving signal; an optical projection system 1b containing a first optical element 1a and for projecting said light signal toward an object of projection; exit side polarizing elements 3b; a holding member 6 for holding them with the liquid crystal display element 2; and cooling medium 5; incident side polarizing elements 3a, wherein, a space is defined by either one of the incident side polarizing elements 3a and the liquid crystal display element 2, the first optical element 1a, between the liquid crystal display element 2 and the first optical element 1a, and the holding member 6, and said space is filled up with the cooling medium 5.
摘要:
When a projection lens system used for a rear projection type image display apparatus has a first lens group having an aspherical lens surface, a second lens group, a third lens group sharing almost all the positive refractive power of the overall system, a fourth lens group having an aspherical lens surface, a fifth lens group, and a sixth lens group including a lens having a profile of aspherical surface in which the concave surface thereof faces the screen side and the refractive power in the marginal area is weaker than the refractive power around the optical axis, a projection lens system having a large aperture ratio (low F-number), high focus, wide field angle, and sufficient marginal light amount ratio can be realized at a low cost. When a predetermined opening portion is formed in the projection lens and lens barrel, the lens elements are cooled by air suction and exhaust and the lowering of the lens performance due to temperature change can be prevented. When a flange is arranged in a suitable location of the opening portion, entry of a foreign material from the opening portion and light leakage from the inside are prevented and the contrast performance of the projection type image display apparatus can be prevented from lowering.
摘要:
A grinding head unit is constituted by a grinding wheel, a drive device for rotating the grinding wheel, and a movement device for moving the grinding wheel. When vibration of a mill roll is applied to the grinding wheel, a plain wheel integral with an abrasive layer of the grinding wheel and having an elastically deforming function is deflected to absorb the vibration energy. The contact force between the abrasive layer and the mill roll is measured for determining a profile of the mill roll. The mill roll can be thereby ground into a target profile while absorbing the vibration transmitted from the mill roll and measuring the profile of the mill roll, without causing any chattering marks.
摘要:
Upper and lower working rolls 2a, 2b are ground while moving respective grindstone devices 3a, 3b in reverse directions, whereby the region of grinding for the upper working roll 2a and that for the lower working roll 2b are maintained in symmetry with respect to the center of rolls, one on the operating side and the other on the driving side. By this arrangement, it is possible to equalize the coefficients of friction on the operating side and the driving side, and to prevent meandering of the rolling stock 6 as well as drawing (squeezing) or bad product shape due to the meandering from occurring. The timings to start grinding by the grindstone devices 3a, 3b are set to be substantially the same, and the velocities of movement of the grindstone devices 3a, 3b in the axial direction of the working rolls are set to be equal, whereby the difference in frictional coefficient due to grinding in the longitudinal direction of the rolls can stably be kept small.