Surveying instrument

A surveying instrument, comprising a first image pickup unit for obtaining a first image in a collimating direction, a second image pickup unit for obtaining a second image highly magnified than the first image pickup unit, a display unit for displaying the images obtained by the first image pickup unit and the second image pickup unit, and a control unit for magnifying and continuously displaying the first image and the second image on the display unit.

BACKGROUND OF THE INVENTION

The present invention relates to a surveying instrument for performing light wave distance measurement by projecting a laser beam to an object to be measured. In particular, the present invention relates to a surveying instrument, which comprises a zooming function to continuously magnify an angle of view of a collimated image.

First, description will be given on a conventional type surveying instrument referring toFIG. 7.

FIG. 7represents a surveying instrument main unit1. The surveying instrument main unit1is installed on a tripod (not shown).

The surveying instrument main unit1primarily comprises a leveling unit2mounted on a tripod, a base unit3mounted on the leveling unit2, a frame unit4mounted on the base unit3so that the frame unit4can be rotated horizontally around a vertical axis, and a telescope unit5mounted so that the telescope unit5can be rotated around a horizontal axis on the frame unit4in a top-to-bottom direction.

The frame unit4comprises a display unit6, an operation unit7, and a control unit provided inside (not shown), etc. The telescope unit5comprises a first telescope8which is a simple collimating telescope and a second telescope9which has fixed high magnification, which collimate an object to be measured. Further, the first telescope8and the second telescope9have optical axes running in parallel to each other. The second telescope9has high magnification. For example, magnification of the second telescope9is 30 times (30×).

On the telescope unit5, there are provided a collimating optical system including the first telescope8and the second telescope9and a distance measuring optical system. After a collimating position (a measuring point) has been determined by the first telescope8and the second telescope9, light wave distance measurement is performed via the distance measuring optical system.

In case the collimating position is to be determined, because the second telescope9has high magnification and has narrower visual field, a collimating direction is roughly determined by the first telescope8, which has wider visual field. Further, the collimating position is determined by the second telescope9.

In the conventional type surveying instrument, collimation is performed by the first telescope8which is a simple collimating telescope and the second telescope9which has fixed high magnification. When the collimating direction is determined or the object to be measured is collimated by the first telescope8and the collimating position is to be determined by the second telescope9, magnification is very much different between the two telescopes. As a result, the collimating position or the object to be measured may be out of the visual field of the second telescope9. In this case, the collimating direction must be adjusted again by the first telescope8.

Or, when the collimating position is determined by the second telescope9, it may be wanted sometimes to observe more closely around the collimating position. Because the second telescope9has fixed magnification, it is not possible to observe more closely than the visual recognition by the second telescope9.

A zoom lens is used in optical instruments such as a camera, and the magnification can be changed without changing the collimating direction. However, when magnification is changed by the use of the zoom lens, the collimating position is moved within the visual field. In this respect, this is not adopted for a surveying instrument, which requires high accuracy.

A surveying instrument comprising the first telescope8and the second telescope9is disclosed in JP-A-2003-27935.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a surveying instrument, by which it is possible to perform digital zooming from low magnification to high magnification by using a digital image and to avoid deterioration of image quality due to digital zooming.

To attain the above object, the present invention provides a surveying instrument comprising a first image pickup unit for obtaining a first image in a collimating direction, a second image pickup unit for obtaining a second image highly magnified than the first image pickup unit, a display unit for displaying the images obtained by the first image pickup unit and the second image pickup unit, and a control unit for magnifying and continuously displaying the first image and the second image on the display unit. Also, the present invention provides the surveying instrument, wherein the images obtained by the first image pickup unit and the second image pickup unit are a first digital image and a second digital image respectively. Further, the present invention provides the surveying instrument, wherein the control unit magnifies and displays the first digital image up to magnification of the second image pickup unit, and the control unit magnifies and displays the second digital image when magnification of the image is more than the magnification of the second image pickup unit. Also, the present invention provides the surveying instrument, wherein the control unit continuously magnifies and displays the first digital image up to magnification of the second image pickup unit, and the control unit continuously magnifies and displays the second digital image when magnification of the image is more than the magnification of the second image pickup unit. Further, the present invention provides the surveying instrument, wherein the control unit magnifies and displays the first digital image stepwise up to magnification of the second image pickup unit, and the control unit magnifies and displays the second digital image stepwise when magnification of the image is more than the magnification of the second image pickup unit. Also, the present invention provides the surveying instrument, wherein the display unit comprises with a touch panel, and the control unit magnifies and displays the image around a position specified by the touch panel.

The present invention provides a surveying instrument, which comprises a first image pickup unit for obtaining a first image in a collimating direction, a second image pickup unit for obtaining a second image highly magnified than the first image pickup unit, a display unit for displaying the images obtained by the first image pickup unit and the second image pickup unit, and a control unit for magnifying and continuously displaying the first image and the second image on the display unit. As a result, it is possible to magnify an image without causing deviation of the collimating position. Also, magnifying is performed based on a plurality of acquired images having different magnification. Therefore, it is possible to perform zooming from lower magnification to higher magnification, and it is also possible to avoid the deterioration of image quality due to zooming.

The present invention provides a surveying instrument, wherein the control unit magnifies and displays a first digital image stepwise up to magnification of the second image pickup unit, and the control unit magnifies and displays the second digital image stepwise when magnification of the image is more than the magnification of the second image pickup unit. Thus, it is possible to attain the desired magnification in the range from lower magnification to higher magnification.

The present invention provides a surveying instrument, wherein the display unit comprises a touch panel, and the control unit magnifies and displays the image around a position specified by the touch panel. As a result, a magnified image in the required collimating direction can be obtained without accurately adjusting the collimating direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed description will be given below on the best mode of the invention for carrying out the present invention.

Referring toFIG. 1toFIG. 3, description will be given on a first embodiment of the present invention.

FIG. 1represents an external view of a surveying instrument main unit1according to the present invention. Basic structure of the surveying instrument main unit1is the same as the surveying instrument main unit1shown inFIG. 7, and detailed description on the basic structure of the surveying instrument main unit1is not given here.

An operation unit7of the surveying instrument main unit1comprises a zoom switch45and a zoom changeover switch46.

FIG. 2shows general arrangement of a surveying instrument. In the figure, reference numeral1denotes the surveying instrument main unit, and reference numeral10denotes an object to be measured, e.g. a prism.

The surveying instrument main unit1primarily comprises a first image pickup element11, a second image pickup element12, a touch panel13, a display unit6, a key operation/input unit15, a control arithmetic operation unit17, a vertical angle measuring unit18, a horizontal angle measuring unit19, a storage unit21, a distance measuring unit24, a light emitting unit25, a distance measuring light receiving unit26, an image processing unit27, and an optical system31, etc. The control arithmetic operation unit17, the storage unit21, etc. make up together a control unit16. The optical system31, the first image pickup element11, the second image pickup element12, the image processing unit27, etc. make up together an image pickup unit.

The touch panel13is provided on the display unit6so that a central position of magnification zooming (to be described later) can be indicated at a position where the touch panel13is touched. When a distance is measured, a surveying operator instructs, from the key operation/input unit15, a measurement starting command, measuring conditions, etc., zooming operation and changing over of zoom magnification.

The image pickup unit comprises a first image pickup unit28, which contains the optical system31, the first image pickup element11, etc., and a second image pickup unit29, which contains the optical system31, the second image pickup element12, etc. The results of photodetection from the first image pickup element11and the second image pickup element12are respectively inputted to the image processing unit27. Then, signal processing is performed to turn the results of photodetection to a digital image signal for each frame at the image processing unit27. The image signal is stored in the storage unit21via the control arithmetic operation unit17.

On the display unit6, measuring conditions at the measurement, a measurement result, or an image taken in a collimating direction, or a result of image processing are displayed.

The control arithmetic operation unit17is a CPU, for instance. By the command form the key operation/input unit15, the control arithmetic operation unit17carries out starting and execution of programs (to be described later), control and processing of signals, calculation, and driving and control, etc. of the display unit6and the distance measuring unit24.

The control arithmetic operation unit17carries out calculation based on signals from the vertical angle measuring unit18, the horizontal angle measuring unit19and the distance measuring unit24, and measures a vertical angle, a horizontal angle, a distance, etc.

The each digital image signal inputted from the image processing unit27is associated with measurement data when the image signal is picked up, e.g. a vertical angle signal from the vertical angle measuring unit18, a horizontal angle signal from the horizontal angle measuring unit19, and a distance signal from the distance measuring unit24. The results are stored in the storage unit21, and the measurement data are accumulated. The data thus accumulated can be called out as a numerical value alone or together with the image.

With respect to association of each image signal with the measurement data, a recording area is prepared for each measuring point at the storage unit21, and further, an image signal storage area and a measurement data storage area are prepared in the recording area. The image signal is associated with the measurement data for each measuring point, and the results are recorded. Or, an image signal storage area and a measurement data storage area are prepared in the storage unit21. The image signal and the measurement data are separated from each other and are stored in the image signal storage area and the measurement data storage area respectively, and a management data to link the image data with the measurement data. Thus, association is performed by the above method or the like already known.

The vertical angle measuring unit18measures a vertical angle with respect to a horizontal line when the prism10is collimated by the optical system31. The horizontal angle measuring unit19measures a horizontal angle of the prism10with respect to a reference direction when a predetermined direction is defined as the reference direction.

The distance measuring light receiving unit26receives a distance measuring light30reflected by the prism10. Each of the first image pickup element11and the second image pickup element12is an image sensor, e.g. a photodetection element comprising an aggregate of a multiple of pixels such as a CCD, a CMOS sensor, etc. An address of each pixel (a position on the image pickup element) can be specified. An image obtained from a relay lens41(to be described later) is received by the first image pickup element11, and an image obtained via the second telescope9is received by the second image pickup element12, respectively.

In the storage unit21, there are a sequence program, an image processing program, and a program for displaying image data on the storage unit6, etc. The sequence program performs measurement. The image processing program performs image processing, e.g. magnifying or reducing in size of an image around an optical axis based on image signals from the first image pickup element11and the second image pickup element12. As the storage unit21, a semiconductor memory, etc. incorporated in the surveying instrument main unit1or various types of recording mediums, which are connectable to or removably mounted on the surveying instrument main unit1such as FD, CD, DVD, RAM, ROM, a hard disk, a memory card, etc. may be adopted.

The zoom switch45of the operation unit7is a switch for performing operation to magnify or to reduce in size of the image on the display unit6. The image can be magnified or reduced in size with the collimating position fixed at a center of the display unit6. The zoom changeover switch46can change the zoom magnification. In one selection, the zoom magnification is 1 to 30 times (1 to 30×). In another selection, the zoom magnification is 30 to 300 times (30 to 300×). The touch panel13can indicate the center of zoom on the touch panel. The collimating position is selected by a finger or by a touch pen from a display image on the display unit6, and the image can be magnified and displayed with the selected collimating position at the center. In case the touch panel13is used, there is no need to correct the collimating position by using the telescope8.

FIG. 3shows an optical system of a surveying instrument according to the first embodiment of the invention.

An objective lens33, a reflection mirror34, a dichroic mirror35, a focusing lens36, and an erect image prism37are arranged on an optical axis32.

The objective lens33is designed as an aperture lens, and the relay lens41is arranged so that an optical axis of the relay lens41is aligned with the optical axis32at the aperture of the objective lens33.

A relay lens42and the first image pickup element11are arranged on a reflection light optical axis of the reflection mirror34. The first image pickup element11sends the result of photodetection to the image processing unit27as an image signal by collecting pixel signals of individual pixels.

The dichroic mirror35is an optical element, which reflects the distance measuring light30and allows natural light to pass. On the reflection light optical axis of the dichroic mirror35, a reflection prism43is disposed. The reflection prism43has two reflection surfaces43aand43brunning perpendicularly to each other. The light emitting unit25is arranged to face to the reflection surface43a, and the distance measuring light receiving unit26is arranged to face to the reflection surface43b. The light emitting unit25is driven by the distance measuring unit24and emits light. The light emitting unit25emits the distance measuring light30, preferably a light with a wavelength different from a wavelength of natural light, e.g. an infrared light.

The distance measuring light30is reflected by the reflection surface43aand the dichroic mirror35, and the distance measuring light30is turned to a parallel luminous flux by the objective lens33and is projected toward the prism10. After being reflected by the prism10and converged by the objective lens33, the distance measuring light30is reflected by the dichroic mirror35and is received by the distance measuring light receiving unit26. The distance measuring light receiving unit26sends a photodetection signal to the distance measuring unit24.

At the distance measuring unit24, a distance to the prism10is measured based on a result of photodetection of the distance measuring light30by the distance measuring light receiving unit26and based on a result of photodetection of internal reference light (not shown). The result of the measurement is sent to the control arithmetic operation unit17.

The erect image prism37has a plurality of reflection surfaces and projects an incident inverted image as an erect image. At least one of the reflection surfaces is designed as a half-mirror. The natural light entering from the objective lens33passes through the dichroic mirror35and enters the erect image prism37. The erect image prism37projects an image of the prism10as an erect image. Also, a part of the incident light is split and separated and is projected.

By adjusting the focusing lens36along the optical axis32, an erect image is formed on a reticle38, and the image on the reticle38can be recognized by a measuring operator via an ocular lens39. The part of the incident light thus split forms an image on the second image pickup element12. The second image pickup element12sends the photodetection result as an image signal by collecting pixel signals of individual pixels to the image processing unit27.

The image processing unit27performs conversion and processing, etc. of the image signal from the first image pickup element11and the image signal from the second image pickup element12to digital image signals or the like. The image processing unit27sends the digital image signals to the control arithmetic operation unit17. The control arithmetic operation unit17stores the digital image data signal thus sent out to the storage unit21.

The relay lens41, the reflection mirror34, and the relay lens42make up together a first collimating optical system. The first collimating optical system and the first image pickup element11make up together the first image pickup unit28. Optical magnification of the first collimating optical system is 1 time (1×), for instance. The objective lens33, the focusing lens36, and the erect image prism37make up together a second collimating optical system, and the second collimating optical system and the second image pickup element12make up together the second image pickup unit29. Optical magnification of the second collimating optical system is 30 times (30×), for instance.

Description will be given below on operation.

The prism10is installed at a measuring position. By operating a key as required on the operation unit7, power is turned on to the surveying instrument main unit1. The prism10is collimated by the first telescope8, and the prism10is adjusted to align with a center of a visual field. Or, the collimating direction may be roughly determined by the first telescope8.

An image formed on the first image pickup element11via the relay lens41and the relay lens42is displayed on the display unit6, and the image is stored at the storage unit21via the image processing unit27and the control arithmetic operation unit17.

When it is wanted to magnify an image of the display unit6, the zoom switch45on the operation unit7is operated. A signal from the zoom switch45is inputted to the control arithmetic operation unit17. The control arithmetic operation unit17starts and executes the image processing program. From the image data stored in the storage unit21, an area around the optical axis and corresponding to the magnification is cut off, and the image is magnified and displayed on the display unit6. Magnification is set to 1 to 30 times (1 to 30×), for instance.

In case a magnifying center is indicated by using the touch panel13, an image around the indicated position is magnified and displayed on the display unit6. Therefore, when the touch panel13is used, collimation by the first telescope8may be carried out roughly.

The image displayed on the display unit6is always magnified around the optical axis or around the indicated position. Thus, no deviation occurs from the displayed collimating direction or from the center of the image.

Based on the magnified image, it is possible to judge whether or not the collimating direction is directed toward the object to be measured (the prism10). If there is any difference, the collimating direction is corrected while watching the image. After the correction, it is confirmed whether or not the collimating direction is directed toward the prism10by the second telescope9. The optical axis of the first telescope8is running in parallel to the optical axis of the second telescope9, and the optical axis of the first telescope8is running closer to the optical axis of the second telescope9. By aligning the collimating direction on the first telescope8, the collimating direction by the second telescope9can be corrected.

An image obtained by the second telescope9is projected to the second image pickup element12via the erect image prism37, and an image formed on the second image pickup element12is stored in the storage unit21via the image processing unit27and the control arithmetic operation unit17. The image received at the second image pickup element12is displayed on the display unit6.

When an image magnified by more than 30 times is to be displayed, the zoom changeover switch46is changed over, and zoom magnification is changed.

The zoom switch45on the operation unit7is operated. The image processing program is started and executed. From the image data stored in the storage unit21, an area around the optical axis and corresponding to the magnification is cut off, and the image is magnified and displayed on the display unit6. An image magnified by 30 to 300 times (30 to 300×) is displayed on the display unit6. As described above, the image displayed on the display unit6is always magnified around the optical axis. Thus, no deviation occurs on the collimating position even when the image displayed is magnified at high magnification.

When an image is magnified, an image may be continuously magnified as shown inFIG. 4or an image may be magnified stepwise as shown inFIG. 5. In any case, it is digital zooming based on the processing of digital image signals, and a magnified image in any size can be obtained. For the zooming of 30 times or more, the deterioration of image quality can be avoided because the image obtained by the second image pickup unit29is magnified.

FIG. 6represents a second embodiment of the invention. In this second embodiment, the optical system of the first image pickup unit28is separately constructed from the optical system of the second image pickup unit29, and the optical system of the first image pickup unit28is commonly used with the first telescope8.

InFIG. 6, the same component as shown inFIG. 3is referred by the same symbol.

The light emitting unit25is arranged on a reflection light optical axis of the reflection mirror34, and the distance measuring light receiving unit26is arranged on a reflection light optical axis of the dichroic mirror35. The distance measuring light30reflected by the prism10and converged by the objective lens33is reflected by the dichroic mirror35and is received by the distance measuring light receiving unit26. The distance measuring light receiving unit26sends a photodetection signal to the distance measuring unit24.

Natural light from the prism10passes through the dichroic mirror35and enters the erect image prism37. By adjusting the focusing lens36along the optical axis32, an erect image is formed on the reticle38. The image on the reticle38can be visually recognized by a measuring operator via the ocular lens39. The split part of the incident light forms an image on the second image pickup element12. The second image pickup element12turns the photodetection result to an image signal by collecting pixel signals of individual pixels and sends the image signal to the image processing unit27.

An image obtained through the telescope8is formed on the first image pickup element11via the relay lens41. The first image pickup element11turns the photodetection result to an image signal by collecting pixel signals of individual pixels and sends the image signal to the image processing unit27.

The image processing unit27performs conversion and processing, etc. of the image signal from the first image pickup element11and the image signal from the second image pickup element12to a digital image signal or the like and sends the digital image signal to the control arithmetic operation unit17. The control arithmetic operation unit17stores the digital image data signal thus sent out to the storage unit21.

The operation in the second embodiment is the same as the operation of the first embodiment, and detailed description is not given here.