JPH0630708U - Telescope for surveying instrument - Google Patents

Abstract

(57) [Summary] [Purpose] By projecting the illumination light from the rough surface of the forward-reverse conversion prism, the reticle is uniformly illuminated without blocking the light flux of the telescope, and the optical adjustment of the illumination system is unnecessary. [Structure] In a telescope for a surveying instrument, which comprises a collimation optical system including a positive / negative conversion prism and a reticle arranged on the optical axis of the collimation optical system and having a collimation mark, A light source for reticle illumination is arranged so as to face a surface other than the light beam reflecting surface and the light beam transmitting surface in the collimation optical path. The surfaces other than the light flux reflecting surface and the light flux transmitting surface are usually rough surfaces, and the light projected from either of these surfaces becomes scattered light and is projected onto the reticle from the forward / backward conversion prism.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a telescope for a surveying instrument, and more particularly to a technique for a telescope having a reticle having a collimation mark so that the reticle can be accurately illuminated without blocking the light flux of the telescope.

[0002]

[Prior art]

 Generally, a collimation optical system of a telescope used for a range finder and a surveying instrument is provided with a reticle arranged on the optical axis of the collimation optical system and having a collimation mark such as a crosshair. Has been. There is also provided means for illuminating the reticle in case of using such a surveying instrument telescope in a dark place.

FIG. 6 shows a schematic structure of a conventional telescope for a surveying instrument having a function of illuminating a reticle. The telescope shown in the figure is basically composed of an objective lens 11, a focusing lens 13, a positive / negative conversion prism 14 such as a porpo prism, a reticle 15, and an eyepiece lens 16. Further, in order to illuminate the reticle 15, a small mirror 18 is arranged behind the objective lens 11 in a direction inclined by 45 degrees with respect to the optical axis, and the small mirror 18 is projected from the direction perpendicular to the optical axis. The light source 17 for reticle illumination is provided. Further, when a surveying instrument using such a telescope is used for distance measurement, the dichroic prism 12 is arranged on the optical axis. An example of a lightwave rangefinder in which such a telescope is used is shown in Japanese Patent Laid-Open No. 58-30614.

In the telescope for a surveying instrument of FIG. 6, light from a subject (not shown) passes through an objective lens 11, a focusing lens 13, an up-and-down conversion prism 14, a reticle 15 and an eyepiece lens 16 and is seen by an observer's eye. To reach. In this case, the light from the light source 17 for reticle illumination is projected onto the small mirror 18, reflected by the small mirror 18 in the optical axis direction, and irradiated onto the reticle 15 via the focusing lens 13 and the forward / reverse conversion prism 14. Then, the reticle 15 is illuminated. This makes it possible to see the collimation mark provided on the reticle even in a dark place.

[0005]

[Problems to be solved by the device]

 However, in such a conventional telescope, since the small mirror 18 is on the optical axis of the telescope, there is a disadvantage that the light flux of the telescope is blocked. For this reason, the field of view becomes dark when the observer looks at the subject, and the light projected onto the subject through the dichroic prism 12 and part of the reflected light from the subject are lost when distance measurement is performed. was there.

There is also a disadvantage that the position and angle of the small mirror 18 must be adjusted in order to illuminate the reticle 15 evenly.

Therefore, in view of the problems in the apparatus of the conventional example, the object of the present invention is to provide a simple structure without blocking the light flux of the telescope and without requiring optical adjustment of the illumination system. The purpose is to provide a telescope for a surveying instrument that can accurately illuminate a reticle.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, a telescope for a surveying instrument according to the present invention has a collimation optical system including a positive / negative conversion prism, and a collimation mark disposed on the optical axis of the collimation optical system. A reticle and a reticle illuminating light source arranged to face a surface other than a light beam reflecting surface and a light beam transmitting surface in the collimation optical path of the positive-inverted conversion prism.

Further, it is convenient that the surfaces other than the light beam reflecting surface and the light beam transmitting surface in the collimation optical path of the positive-inverted conversion prism are roughened surfaces.

[0010]

In the above structure, the light emitted from the reticle illumination light source is the surface of the forward / inverted conversion prism facing the light source, that is, other than the light flux reflecting surface and the light flux transmitting surface in the collimation optical path of the forward / inverted prism. Incident on the surface of. This incident light is reflected by each surface of the prism, and some of the projected light reaches the reticle and illuminates the reticle. In particular, by setting the surfaces other than the light beam reflecting surface and the light beam transmitting surface in the collimation optical path of the forward / reverse conversion prism as rough surfaces, the light projected from the reticle illumination light source is scattered by these rough surfaces. Next, it reaches the reticle through many reflections in the prism. Due to the scattering on the roughened surface, the illumination light is free from the unevenness of the light amount due to the directivity of the light source, so that the reticle can be uniformly illuminated, and the position and angle of the light source need not be strictly adjusted. Since the illuminance required to actually illuminate the reticle is extremely small, a small light source, such as a small visible light LED, is used as the light source for the reticle illumination even considering the scattering on the rough surface. Can be configured with.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a telescope for a surveying instrument according to an embodiment of the present invention. The telescope shown in the figure includes an objective lens 11, and if necessary, a dichroic prism 12, a focusing lens 13, a Porro prism 14, a reticle 15, and an eyepiece lens 16, like the telescope shown in FIG. Further, the telescope shown in FIG. 1 is provided with an illuminating light source 19 which is arranged so as to face one side surface of the Porro prism 14, for example.

In such a telescope, light from a subject (not shown) passes through the objective lens 11, the dichroic prism 12, the focusing lens 13, the Porro prism 14, the reticle 15 and the eyepiece 16 and reaches the observer's eye. . Then, the light emitted from the illumination light source 19 enters as scattered light from the rough sliding surface on the side surface of the Porro prism 14 and illuminates the reticle 15 after undergoing many reflections in the Porro prism 14.

FIG. 2 shows the positional relationship between the Porro prism 14 and the light source 19. That is, the light source 19 is arranged so as to face one side surface 20 of the small prism 23 of the three small prisms 21, 22 and 23 that form the Porro prism 14. The side surface 20 is a rough surface.

FIG. 3 is an expanded view of the Porro prism 14 shown in FIG. As shown in FIG. 3, the light emitted from the reticle illumination light source 19 becomes scattered light on the rough surface 20 and reaches the small prism 21 through the small prism 23, the small prism 22, and the small prism 21, and reaches the small prism 21. The reticle 15 on the optical axis of the telescope is illuminated.

FIG. 4 is a perspective view showing the Porro prism 14. As is apparent from the figure, the Porro prism 14 is composed of a combination of three small prisms 21, 22 and 23. The reticle illumination light source 19 is arranged so as to face one side surface 20 of the Porro prism 23.

FIG. 5 shows a structure of a roof prism that can be used instead of the Porro prism. The roof prism is composed of, for example, a combination of two small prisms 24 and 25. In this case, the reticle illumination light source 19 is arranged so as to face one side surface 26 of the small prism 25, for example.

In general, a Porro prism, a roof prism, or the like has a rough surface other than the light beam reflecting surface and the light beam transmitting surface in order to cut harmful light. Therefore, the illumination light source 19 can be arranged so as to face such an arbitrary rough surface.

[0018]

[Effect of device]

 As described above, according to the present invention, since there is no component such as a small mirror on the optical axis of the telescope as in the past, the light flux of the telescope is not blocked and the number of components used for reticle illumination is reduced. it can. Further, since the reticle illumination light can be made incident through the rough surface, it is not necessary to adjust the position of the illumination light source and the illumination unevenness does not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a schematic configuration of a telescope for a surveying instrument according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a Porro prism and a reticle illumination light source used in the telescope of FIG.

FIG. 3 is a development view for explaining how light projected from an illumination light source reaches a reticle.

FIG. 4 is a perspective view showing a positional relationship between a Porro prism and an illumination light source used in the telescope of FIG.

FIG. 5 is a perspective view showing a positional relationship between a roof prism and an illumination light source used in a surveying instrument telescope according to another embodiment of the present invention.

FIG. 6 is a cross-sectional explanatory view showing a schematic structure of a conventional telescope for a surveying instrument.

[Explanation of symbols]

 11 Objective Lens 12 Dichroic Prism 13 Focusing Lens 14 Porro Prism 15 Reticle 16 Eyepiece 17, 19 Reticle Illumination Light Source 18 Small Mirror 20, 26 Facing Faces 21, 22, 23, 24, 25 Small Prism

Claims (4)

[Scope of utility model registration request] 1. A collimating optical system including a positive / negative conversion prism,
The reticle disposed on the optical axis of the collimation optical system and having a collimation mark, and the reticle facing the surface other than the light beam reflecting surface and the light beam transmitting surface in the collimating optical path of the positive / negative conversion prism. A telescope for a surveying instrument, comprising: a light source for reticle illumination. 2. The telescope for a survey instrument according to claim 1, wherein a surface other than the light beam reflecting surface and the light beam transmitting surface in the collimating optical path of the positive-inverted conversion prism is a rough surface. 3. The telescope for a surveying instrument according to claim 1, wherein the positive-inverted conversion prism is a Porro prism. 4. The telescope for a surveying instrument according to claim 1, wherein the up-and-down conversion prism is an erecting prism.