JPH04130918U - Anamorphic Cleanse - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce manufacturing costs and maintain optical performance. [Structure] The anamorphic lens 11 has one surface 12a of the concave cylindrical lens 12 flat and the other surface 12b.
is concave. One surface 1 of the convex cylindrical lens 13
3a is planar, and the other surface 13b is convex.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention allows image information of a predetermined aspect ratio (for example, 16:9) to be convert it into image information with a high contrast ratio (for example, 4:3), record or transmit it, and play it back. Or, after receiving it, perform the reverse conversion to obtain the image information of the original aspect ratio. This relates to the improvement of optical lenses.

0002

[Conventional technology]

In recent years, home displays have become larger, and the so-called home theater We are entering the era of In addition, projection type projectors are now becoming widely popular. ing. On a large screen of 80 inches or more, considering the range of human vision, the screen is A horizontally long and wide screen is desirable. Due to these circumstances, the current NTSC The aspect ratio (the aspect ratio of the screen) is 4:3, while the high-definition The aspect ratio of 16:9 is adopted in the 2nd generation EDTV.

0003 By the way, for example, a high-definition wide screen is different from an NTSC screen. Since the aspect ratio is different, it is not compatible with the NTSC system. Therefore, high-definition Converts the screen aspect ratio to enable recording and transmission in the NTSC format, and A method has been devised and implemented to return the image to its original aspect ratio after it is live or received. this ass An anamorphic lens optically converts the aspect ratio.

0004 A conventional anamorphic lens 1 schematically shown in FIG. 4 is a concave cylindrical lens. In addition to the general configuration consisting of a convex cylindrical lens 2 and a convex cylindrical lens 3, a concave cylindrical lens Both surfaces 2a and 2b of the lens 2 are each concave, and a convex cylindrical lens Both surfaces 3a and 3b of 3 were convex, respectively. Concave cylindrical lens 2 and The convex and convex cylindrical lens 3 has curvature only in the horizontal section along the X1-X2 direction. In other words, there is no curvature in the vertical cross section along the Y1-Y2 direction. The incident optical image is Since it is enlarged only in the X1-X2 direction, use this property to adjust the screen aspect ratio. Conversion becomes possible. In addition, convex cylindrical lens 2 and concave cylindrical lens 3 is afocal type.

[0005] This anamorphic lens 1 is used, for example, in a liquid crystal projector as schematically shown in FIG. 4 is disposed in the rear stage of the projection lens system 6 consisting of lenses 6a to 6g. . 7 is a liquid crystal panel placed before the projection lens system 6. Is it a light source not shown? The light is input to the liquid crystal panel 7, and the optical image output from there is transmitted to the projection lens system. 6 and the anamorphic lens 1 to a screen (not shown) outside the device. imaged.

[0006]

[Problem that the idea aims to solve]

However, in the conventional anamorphic lens 1, the concave cylindrical lens Both surfaces 2a and 2b of the lens 2 are concave, and both surfaces 3a and 3b of the convex cylindrical lens 3 are respectively concave. are each convex, so the most concave portion of both surfaces 2a and 2b of the concave cylindrical lens 2 Coincidence (peak alignment) of generatrix 2a1 and 2b1 at soldering point, convex cylindrical lens Coincidence of generatrix 3a1, 3b1 at the most protruding part of both sides 3a, 3b (peak bubble) ) are required respectively.

[0007] Unlike anamorphic lenses, general spherical lenses The horizontal cross section along the Y1-Y2 direction and the vertical cross section along the Y1-Y2 direction each have a uniform curvature. Therefore, even if eccentricity occurs during the polishing stage of the lens material, for example, the bell clamp type Although it is possible to correct eccentricity in the final process using the automatic centering method, Since the above method cannot be applied to Fick lenses, the process of polishing the lens material is It was necessary to align the peaks on the floor.

[0008] For this reason, the conventional anamorphic lens 1 is difficult to manufacture and costs increase. Was. In addition, the larger the lens diameter, the larger the curvature, which maintains the quality of the lens. It was difficult to do so.

[0009]

[Means to solve the problem]

This invention solves the above problems and combines a concave cylindrical lens and a convex cylindrical lens. In an anamorphic lens consisting of a lindrical lens, the concave cylinder One surface of the linear lens is planar and the other surface is concave, and the convex cylindrical lens Anamorphic lens characterized by one side being flat and the other side being convex. It provides lenses.

0010

【Example】

The present invention will be explained below with reference to the drawings. Figure 1 shows the anamorphic model of this invention. FIG. 2 is a perspective view showing an embodiment of the anamorphic lens according to the present invention. Figure 3(a) is a state diagram of the liquid crystal projector shown in Figure 2. FIG. 3B is an aberration diagram of the liquid crystal projector shown in FIG. In addition Components that are the same as those of the conventional example are given the same reference numerals, and their explanations are omitted.

[0011] The anamorphic lens 11 shown in FIG. The convex cylindrical lens 13 has a flat surface 12a and a concave surface 12b. One surface 13a is planar and the other surface 13b is convex.

0012 In the above anamorphic lens, only one side of the concave cylindrical lens 12 is concave. Only one side of the planar, convex cylindrical lens 13 is convex, making it a concave cylindrical lens. The peak alignment with the lens 12 and the peak alignment with the convex cylindrical lens 13 are incorrect. Because it is necessary, when manufacturing anamorphic lenses with the same lens diameter, use the conventional method. It is easier to manufacture than As a result, manufacturing costs for anamorphic lenses are reduced. can be done. In addition, it is not only easy to manufacture, but also has a large lens diameter. Even the quality of anamorphic lenses is easy to maintain.

[0013] Note that FIG. 2 shows the anamorphic lens 11 placed inside the liquid crystal projector 14. This shows the state diagram. The widths KP, KQ, and KR of the two-dot chain lines are the upper edge of the liquid crystal panel 7. The light amounts at P, the lower end Q, and a point R on the optical axis of the projection lens system 6 are shown, respectively.

[0014] Next, we will discuss the optical characteristics of the anamorphic lens according to the present invention at the same magnification and the conventional The optical properties of the example anamorphic lens were measured with respect to aberrations only. anamorphic The aberrations including the projection lens system 6 were measured, not the aberrations of the lens alone. That is, the aberration in the liquid crystal projector 14 shown in FIG. 2 and the liquid crystal projector shown in FIG. Aberrations at the injector 4 were measured. The lens diameter of the anamorphic lens used is The lens data of the anamorphic lens 11 of this embodiment is the same as that of the conventional example. Lens data of anamorphic lens 1 is shown in Tables 1 and 2. Under the above conditions, true Aberration diagram when using anamorphic lens 11 of the example, conventional anamorphic lens Aberration diagrams when Cleanse 1 is used are shown in FIGS. 3(a) and 3(b). In addition, the aberration is , spherical aberration, astigmatism, and distortion aberration.

[0015]

[Table 1]

[0016]

[Table 2] Referring to FIGS. 3(a) and 3(b), when comparing spherical aberration, astigmatism, and distortion aberration between this example and the conventional example, there was almost no change in spherical aberration and distortion. Also, although sagittal astigmatism has increased slightly, it is within the practical range. This result shows that the anamorphic lens 11 of this example can be used in a liquid crystal projector without any problem.

[0017]

[Effect of the idea]

From the above explanation, the anamorphic lens of this invention is a concave cylindrical lens. This eliminates the need for peak alignment with , and peak alignment with a convex cylindrical lens. Manufacturing anamorphic lenses with the same lens diameter is easier than conventional methods. becomes. As a result, the manufacturing cost of anamorphic lenses can be reduced. There is a big effect. In addition, it is not only easy to manufacture, but also has a large lens diameter. The effect is that it becomes easier to maintain the quality of anamorphic lenses even when It also has.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of an anamorphic lens according to the present invention.

FIG. 2 is a diagram showing an anamorphic lens according to the present invention arranged in a liquid crystal projector.

3(a) is an aberration diagram of the liquid crystal projector shown in FIG. 2, and (b) is an aberration diagram of the liquid crystal projector shown in FIG. 5. FIG.

FIG. 4 is a perspective view showing a conventional anamorphic lens.

FIG. 5 is a diagram showing a state in which a conventional anamorphic lens is arranged inside a liquid crystal projector.

[Explanation of symbols]

11 Anamorphic lens 12 Concave cylindrical lens 12a One side of concave cylindrical lens 12b Other surface of concave cylindrical lens 13 Convex cylindrical lens 13a One side of convex cylindrical lens 13b Other surface of convex cylindrical lens

Claims (1)

[Scope of utility model registration request] 1. An anamorphic lens comprising a concave cylindrical lens and a convex cylindrical lens, wherein one surface of the concave cylindrical lens is planar and the other surface is concave, and one surface of the convex cylindrical lens is planar and the other surface is convex. An anamorphic lens characterized by its shape.