JPS6239817A - Projector - Google Patents

Abstract

PURPOSE:To obtain a small-sized device by shortening the whole optical path length, by providing an optical system which has arranged plural lenses and plural mirrors in parallel roughly. CONSTITUTION:On an optical axis X1 of the first lens 11 of an object side, the first mirror 12 is placed at an interval of a distance l1. The second mirror 13 is placed in parallel roughly to the first lens 11 and also opposed at an interval of a distance l2 to the first mirror 12. An optical axis X2 of the second lens 14 is placed so as to go to parallel to the optical axis X1 of the first lens 11, and it is opposed at an interval of a distance l3 to the second mirror 13. An incident light Y1 from an object (not shown in the figure) passes through the first lens 11, reflected by the first mirror 12 and led to the second mirror 13, reflected and made incident on the second lens 14, and goes to an emitted light Y2 and emitted to a projection surface (not shown in the figure). Accordingly, the whole optical path length l of the optical system goes to about l=l1+l2+l3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical projection device, and particularly to a projection device that forms a mirror of an object on a projection surface.

(Prior Art) Conventionally, a projection device that forms a mirror image of an object on a projection surface has been particularly used in a copying device that has a transfer process. That is, a projection lens system having only one optical axis was used. However, when a monocular lens system is used, its optical conjugate distance becomes relatively long, so it has been difficult to miniaturize a copying apparatus using a monocular lens system as a projection lens system. Therefore, efforts were made to shorten the conjugate distance of the projection lens system in order to downsize copying machines, and as a result, one solution was to replace the projection lens system with multiple lens systems with relatively short conjugate distances, aligned with the optical axis. A projection device formed by a compound eye lens system arranged in a vertical direction has been proposed.For example, as shown in FIG. 6, it is composed of a first lens 1 on the object side and a second lens 2 on the image side. A full-length lens system was used. On this occasion,
The distance t between the first lens 1 and the second lens 2 is the same as the total length of the lens system. In this projection device, each elemental lens system (lens system arranged along the optical axis extending between the object and the projection surface) constituting the compound eye lens system produces an image of each part of the object to be projected on the projection surface. The entire compound eye lens system forms a projected image of the entire object on the projection plane.

For example, in Patent Application Publication No. 8893 published on February 28, 1971, a strip-shaped area of the original to be copied is cleaned in the longitudinal direction of this strip-shaped area and a plurality of element lens systems are arranged. However, a projection device is shown in which each partial image of a band-shaped area is formed on a photoreceptor by these elemental lens systems.

Each elemental lens system of this projection device is composed of three lenses: a front lens, an intermediate lens, and a rear lens.

For such a projection optical system, a projection optical system in which the number of lenses constituting the element lens system is reduced without reducing the brightness of the projected image is disclosed in Japanese Patent Laid-Open No. 122426/1983. All of these were projection devices that simply formed a mirror image of an object on the projection surface at equal magnification.

In other words, it is possible to make the total length of the compound eye lens e system rectangular to make the projection device more compact, or to arrange another optical system within the compound eye lens system, for example, an optical system to enable variable magnification of the am of the object. Furthermore, it was impossible to arrange centers for detecting information such as the amount of light regarding the mirror image of an object.

(Problems to be Solved by the Invention) The present invention has been made for the purpose of solving the above-mentioned conventional problems. This is an attempt to develop a projection device that can be equipped with sensors that detect information such as the amount of light related to mirror images. Furthermore, the present invention provides a projection device that can be easily manufactured by molding.

(Means for solving the problem) As a means for solving the problem, a projection device according to the present invention includes a plurality of lenses and a plurality of mirrors,
a first lens located closest to the object; a first mirror disposed on or near the optical axis of the first lens; and a first lens located in the optical path of the object light reflected by the first mirror. The gist of this is to have a second mirror arranged substantially parallel to the first lens, and a second lens that forms an image of the object light reflected by the second mirror.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows a schematic configuration diagram of a projection device according to the present invention, 1
1, the second lens 14 on the object side is the first mirror;
A first mirror 12 is arranged on the optical axis X1 of the lens 11 at a distance t1.

Further, 13 is a second mirror, and the second mirror i3 is arranged substantially parallel to the first mirror e11, and the second mirror i3 is arranged substantially parallel to the first mirror 12.
and facing each other with a distance t between them. 14 is a second lens on the image side, and the optical axis X of the second lens 14 is the same as the first lens 11.
The projection device is arranged so as to be parallel to the optical axis X1 of the optical axis X1, and is opposed to the second optical axis 13 at a distance t.

An incident ray Y, from an object (not shown) is transmitted through the first lens 1
1, is reflected by the first mirror 12, and guided to the second mirror 13. Then, it is reflected again by the second mirror 3 and the second
Light #Y enters the lens 14 and exits to the projection surface (not shown)
, and is emitted. Therefore, the total optical path length of the optical system in this projection apparatus is approximately twt, +t, +t.

Here, stK''・Distance t between the first lens 11 and the first constant mirror 12, . . . Distance t between the first Z roller 12 and the second lens 13, . . . Between the second mirror 13 and the second lens 14 The total length of the lens system is 1=11=1°.In other words, the total length of the lens system is the distance t between the first lens 11 and the first mirror 12 and the second mirror 13 and 2nd
The length can be the same as the distance t between the lenses 14.

FIG. 2 shows a second embodiment of the projection apparatus according to the present invention, in which the same members as in the previous embodiment are denoted by the same reference numerals.
Tax evasion is omitted. In this embodiment, a pair of mirrors 12m and 13m are provided between the first mirror 12 and the second mirror 13.
are arranged opposite to the first mirror 12 and the second mirror 13 so as to be substantially parallel to each other, and a plurality (six in FIG. 2) of reflecting mirrors 12&+131 arranged in the same manner are arranged. Note that the other configurations are completely the same as the first embodiment described above.

Therefore, incident light Y1 from an object (not shown) passes through the first lens 11 and passes through the first mirror 12 and the plurality of mirrors 12.
The optical path length between the first lens 11 and the second lens 14 is can be made longer without changing the overall length of the lens system.

FIG. 3 shows a third embodiment of the projection device according to the present invention, in which the same members as in the previous embodiment are denoted by the same reference numerals.
Explanation will be omitted. In this embodiment, an optical system 15 having a predetermined function is arranged in the optical path between the first mirror 12 and the second mirror 13. For example, other optical system 15
By arranging an optical system with a zoom function,
The projection device of the present invention can be provided with a zoom mechanism.

The other configurations are completely similar to the first embodiment described above.

FIG. 4 shows a fourth embodiment of a projection device according to the present invention,
The same members as those in the first embodiment are denoted by the same reference numerals, and explanations thereof will be omitted. In this embodiment, a half mirror 16 is used as the first mirror 12, and the other configurations are exactly the same as the embodiment shown in FIG.

Therefore, the incident light MY□ from an object (not shown) is -・
- Light ray Y reaching the projection surface (not shown) by the mirror 16
, the light beam is branched into a light beam Y4 that passes through the half mirror 16. The light ray Y4 transmitted through the half mirror 16 is
The amount of light can be measured by entering the light receiving element 17 placed behind the half mirror 16. For example, if the projection device according to the present invention is used in a copying machine, it can be used as a control signal for the mirror image. . Moreover, the above-mentioned ---7 mirror 16
Behind the light receiving element 17, it is possible to arrange various sensors that sense various information about the mirror image of the object in the middle of the optical system.

FIG. 5 shows a fifth embodiment of the projection device according to the present invention,
The same members as those in the embodiment shown in FIG. 1 are designated by the same reference numerals.
In this embodiment, a plurality of lenses e11 and a plurality of second lenses 14 are arranged in a -dimensional linear array, and a first mirror 12 and a second mirror 1
3 corresponds to the lengths of the first lenses 11 and second lenses 14 arranged in an array. The second mirror 13, the first mirror 12, and the second lens 14 are formed as a husband and wife unit.

Further, not only in this embodiment but also in the embodiments shown in FIGS. 1 to 4, a plurality of first lenses 11 and second lenses 14 may be arranged in a linear array, or 13, the second mirror 12, and the second lens 14 can be formed integrally with each other.

(Effects of the Invention) As explained above, the projection device according to the present invention has an optical system in which a plurality of lenses and a plurality of mirrors are arranged substantially in parallel, so that the total optical length can be significantly shortened. , it is possible to provide a compact projection device.

Furthermore, another optical system can be easily placed in the optical path between the first and second optical systems, and the projection device can be equipped with various functions such as a zoom function.

In addition, by using a no-f mirror as at least one of the plurality of mirrors, it is possible to easily arrange sensors that detect information such as the amount of light regarding the mirror image of the object.
This device has the advantage of being able to detect information signals for processing projected images in real time, and is also extremely effective in terms of construction and manufacturing, as it can integrate the lenses and mirrors that make up the projector.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a configuration example of a projection device according to the present invention, FIG. 2 is a schematic diagram showing a projection device according to a second embodiment of the present invention, and FIG. FIG. 4 is a schematic diagram showing a projection device according to a fourth embodiment of the present invention, and FIG. 5 is a schematic diagram showing a projection device according to a fifth embodiment of the present invention. FIG. 6 is a schematic diagram showing an optical system within a projection apparatus in a conventional example. 11... First lens, 12... First mirror, 12a
. 13m...Reflection mirror, 13...Second electric mirror, 14
...Second lens, 15...Variable magnification optical system, 16...
No. 1-7 mirror, 17...light receiving element, X, #X,...
・Optical axis, Y. ...Incoming ray, Y, ...Outgoing ray, Y, ...＼
Light rays reflected by -7 mirror @1 -, Y4... Light rays transmitted through half mirror. Representative Patent Attorney Hirazu Yamashita

Claims (6)

[Claims] (1) Consisting of a plurality of lenses and a plurality of mirrors, a first lens located closest to the object side, a first mirror disposed on or near the optical axis of the first lens, and the first mirror a second mirror located in the optical path of the object light reflected by the lens and arranged substantially parallel to the first lens; and a second lens for forming an image of the object light reflected by the second mirror. Characteristic projection device. (2) The projection device according to claim 1, characterized in that at least one pair of opposing mirrors is provided in the optical path between the first mirror and the second mirror. (3) The projection apparatus according to claim 1, wherein a half mirror is used as at least one of the first mirror and the second mirror. (4) The projection device according to claim 1, wherein the first lens and the second mirror, and the second lens and the first mirror are each formed or fixed to the same member. (5) The first lens, the first mirror, the second lens, and the second lens.
2. The projection device according to claim 1, wherein the mirrors are arranged in a one-dimensional array. (6) Claim 1, characterized in that a variable magnification lens system is provided in the optical path between the first mirror and the second mirror.
Projection device described in Section 2.