Patent Description:
Conventionally, a total station and a three-dimensional scanner are known as a surveying apparatus that transmits distance-measuring light and acquires coordinates of an irradiation point as measurement data. The coordinates of the irradiation point are acquired by measuring a distance to an irradiation point by receiving reflected distance-measuring light reflected by a measuring object and measuring an angle to the irradiation point by detecting an angle of the distance-measuring light (for example, refer to Patent Literature <NUM>).

In the conventional surveying apparatus, for visual confirmation of acquired measurement data, a display image is created by using an information processing device such as a personal computer and the display image is displayed on a display (for example, refer to Patent Literature <NUM>). Patent Literature <NUM> describes a surveying device comprising a base defining a base axis (A), a support structure arranged to be rotatable around the base axis (A) and defining a rotation axis (B), a light emitting unit for emitting measuring signal and a light receiving unit comprising a detector for detecting reflected measuring signal. In Patent Literature <NUM>, a rotation unit is mounted on the support structure for providing emission and reception of measuring light in defined directions, wherein the rotation unit comprises a rotation body which is mounted rotatable around the rotation axis (B) and the rotation body comprises a scanning mirror which is arranged tilted relative to the rotation axis (B). The device of Patent Literature <NUM> comprises at least one projector fixedly arranged with the support structure, defining a particular optical axis and configured to direct a light pattern at a scene, wherein position and shape of the pattern are controllable by the controlling and processing unit. Patent Literatures <NUM>-<NUM> describe additional state of the art for the present invention.

However, there was no surveying apparatus capable of projecting measurement data onto a real space by using a projector device for visual confirmation of the measurement data.

The present invention has been made in view of these circumstances, and an object thereof is to enable on-site visual confirmation of measurement data by projecting the measurement data onto a measuring object.

In order to achieve the object, a surveying apparatus according to an aspect of the present invention includes a distance-measuring unit configured to transmit distance-measuring light and measure a distance to a measurement point by receiving reflected distance-measuring light reflected by a measuring object; an angle-measuring unit configured to measure an angle to the measurement point by detecting an angle of the distance-measuring light; a control arithmetic unit including a survey unit configured to acquire three-dimensional coordinates of the measurement point as measurement data by performing distance and angle measurements by controlling the distance-measuring unit and the angle-measuring unit, a projection image generating unit configured to generate a projection image for displaying the measurement data on a surface of the measuring object by acquiring a three-dimensional shape of the measuring object based on the measurement data, and a projection control unit configured to control projection of the projection image onto the measuring object; and an image projecting unit including a display element configured to form an image as the projection image, a light irradiating device configured to cause projection light to enter the display element, and a projector lens configured to project the projection image emitted from the display element onto the measuring object.

In the aspect described above, it is also preferable that the projection image generating unit generates, as the projection image, an image displaying the measurement point as a point.

In the aspect described above, it is also preferable that the projection image generating unit generates, as the projection image, an image displaying irregularities on a surface of the measuring object in a recognizable manner.

In the aspect described above, it is also preferable that the surveying apparatus further includes a storage unit configured to store design data of the measuring object, wherein
the projection image generating unit generates an image displaying a difference between the design data and the measurement data in a recognizable manner.

According to the invention, the distance-measuring light is pulsed light, and the surveying apparatus is a laser scanner configured to acquire three-dimensional point cloud data of the measuring object by scanning with the distance-measuring light in the vertical direction and the horizontal direction, and the projection image generating unit generates, as the projection image, an image displaying levels of point cloud density of the three-dimensional point cloud data in a recognizable manner.

In the aspect described above, it is also preferable that an instrument center and an origin of coordinates of the projection image match each other, and an optical axis of the distance-measuring unit and an optical axis of the image projecting unit are configured to be opposed to each other on a common straight line.

According to the aspects described above, the surveying apparatus is configured to generate a projection image for measurement data confirmation and project the projection image onto a surface of a measuring object in a real space, so that the measurement data can be visually and intuitively confirmed on-site.

Preferred embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same configurations are provided with the same reference signs, and corresponding configurations are provided with the same names, and overlapping descriptions are omitted as appropriate. In each drawing, components are properly scaled and schematically illustrated for convenience of description, and may not reflect actual proportions. The following embodiments are examples, and the present invention is not limited to these.

<FIG> is an external view illustrating a state where a surveying apparatus <NUM> according to a first embodiment is projecting a projection image <NUM>. <FIG> is a configuration block diagram of the surveying apparatus <NUM>, and <FIG> is a schematic view describing configurations of a distance-measuring unit <NUM> and an image projecting unit <NUM>. The projection image <NUM> can include various modifications (for example, projection images 6a to 6c) as described later, and the projection image <NUM> is representatively described in a common description.

In the present embodiment, the surveying apparatus <NUM> is a so-called motor-driven total station. The surveying apparatus <NUM> is installed at a known point via a tripod <NUM> and a leveling base <NUM> mounted on the tripod <NUM>. In appearance, the surveying apparatus <NUM> includes a base portion 4a to be removably mounted on the leveling base <NUM>, a bracket portion 4b provided horizontally rotatably <NUM>° around an axis H-H on the base portion 4a, and a telescope 4c provided vertically rotatably about an axis V-V in a recessed portion <NUM> of the bracket portion 4b.

As illustrated in <FIG>, the surveying apparatus <NUM> includes the distance-measuring unit <NUM>, an angle-measuring unit <NUM>, a rotation driving unit <NUM>, a control arithmetic unit <NUM>, a display unit <NUM>, a storage unit <NUM>, the image projecting unit <NUM>, and an operation unit <NUM>.

The distance-measuring unit <NUM> is disposed inside the telescope 4c, and generally includes, as illustrated in <FIG>, a light emitting element <NUM>, a distance-measuring optical system <NUM>, and a light receiving element <NUM>. The distance-measuring unit <NUM> emits distance-measuring light L from the light emitting element <NUM> through the distance-measuring optical system <NUM> to irradiate a measuring object through a double-sided mirror <NUM>, and receives reflected light La from the measuring object by the light receiving element <NUM> through the double-sided mirror <NUM> and the distance-measuring optical system <NUM>. Based on a phase difference between a light emission signal and a light reception signal acquired by the distance-measuring unit <NUM>, a distance to the irradiation point can be measured. The distance-measuring unit <NUM> is not limited to this, and may be provided with a publicly known configuration included with a light wave distance meter. For example, the distance-measuring unit <NUM> can further include an eyepiece lens, etc., for enabling a user to perform collimation toward a collimation direction.

The double-sided mirror <NUM> is between the distance-measuring unit <NUM> and the image projecting unit <NUM>, and is fixed to the telescope 4c and rotates about the axis V-V integrally with the telescope 4c. The double-sided mirror <NUM> reflects the distance-measuring light L by one surface and reflects projection light M by the other surface so that optical axes of the distance-measuring light L and the projection light M advance toward directions opposite to each other on the same axis.

The angle-measuring unit <NUM> includes a horizontal angle detector <NUM> and a vertical angle detector <NUM>. The horizontal angle detector <NUM> and the vertical angle detector <NUM> are, for example, rotary encoders.

The rotation driving unit <NUM> includes a horizontal rotation driving unit <NUM> and a vertical rotation driving unit <NUM>. The horizontal rotation driving unit <NUM> is a motor, and is provided on the base portion 4a and rotates the bracket portion 4b horizontally about the axis H-H. The horizontal angle detector <NUM> is provided on a rotary shaft portion of the horizontal rotation driving unit <NUM>, and can detect a horizontal angle of the bracket portion 4b, that is, the horizontal angle detector <NUM> can detect a horizontal angle of the collimation direction of the telescope 4c.

The vertical rotation driving unit <NUM> is a motor, and is provided on the bracket portion 4b and rotates the telescope 4c vertically about the axis V-V. The vertical angle detector <NUM> is provided on a rotary shaft portion of the vertical rotation driving unit <NUM>, and can detect a vertical angle of the collimation direction of the telescope 4c. Detection signals acquired by the distance-measuring unit <NUM> and the angle-measuring unit <NUM> are input into the control arithmetic unit <NUM>.

The display unit <NUM> is, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, etc. The display unit <NUM> displays survey results and operation screens, etc., according to control of the control arithmetic unit <NUM>.

The storage unit <NUM> is a recording medium that stores, describes, saves, and transmits information in a computer-processable form, and stores various programs that fulfill functions of the control arithmetic unit <NUM> including functions of functional units described later. In addition, the storage unit <NUM> stores measurement data acquired by a survey unit <NUM> and a projection image <NUM> generated by a projection image generating unit <NUM>. As the storage unit <NUM>, a magnetic disc such as a hard disc drive, a magneto optical disc such as a CD (Compact Disc) and a DVD (Digital Versatile Disc), or a semiconductor memory such as a flash memory and a RAM (Random Access Memory) can be adopted.

The image projecting unit <NUM> is a projector device generally including a light irradiating device <NUM>, a display element <NUM>, and a projector lens <NUM> as illustrated in <FIG>.

The light irradiating device <NUM> is a device including a light source (not illustrated) and configured to irradiate visible light as projection light M toward a display element <NUM> through a projecting optical system <NUM> and the double-sided mirror <NUM>. As the light irradiating device <NUM>, a color-separation type is adopted as an example. As the light source, a semiconductor light emitting element such as an LED (Light Emitting Diode) or a laser diode, or a lamp (halogen lamp, xenon lamp, etc.) can be adopted.

The display element <NUM> is a DMD (Digital Micromirror Device), a transmissive liquid crystal display panel, or a reflective liquid crystal display panel, having a plurality of pixels two-dimensionally arrayed. When the display element <NUM> is a DMD, pixels of the display element <NUM> are movable micromirrors, and when the display element <NUM> is a liquid crystal display panel, pixels of the display element <NUM> are liquid crystal shutter elements.

When the light irradiating device <NUM> is a color-separation type, the light irradiating device <NUM> has a white light source and a color separator, etc., and white light emitted from the white light source is separated into red (R), green (G), and blue (B) that are the three primary colors of light by the color separator. In this case, the display element <NUM> is prepared for each color, and the display elements <NUM> are irradiated with lights in the multiple colors, and lights transmitted through or reflected by the respective display elements <NUM> are synthesized.

As the light irradiating device <NUM>, without being limited to the color-separation type, a time-division type, and an independent light source type which are adopted in a general projector device can be adopted. In each case, a display element <NUM> corresponding to the light irradiating device <NUM> can be adopted.

The projector lens <NUM> projects a display image formed by the display element <NUM> onto a measuring object. The projector lens <NUM> is capable of adjusting focusing and adjusting a focal length. The projector lens <NUM> is driven by a lens driving unit (not illustrated).

The lens driving unit performs zooming and focusing by driving lenses constituting the projector lens <NUM>. Zooming and focusing may be performed by a user's operation, or may be performed by control of a projection control unit <NUM> described later.

The image projecting unit <NUM> is provided inside the telescope 4c as well as the distance-measuring unit <NUM>. The distance-measuring unit <NUM> and the image projecting unit <NUM> are configured so that, for example, an optical axis of the distance-measuring light L of the distance-measuring unit <NUM> and an optical axis of the projection light M from the projecting unit are opposed to each other on a common axis. The common axis is an axis on the collimation axis of the telescope 4c passing through an instrument center O. Here, the instrument center O is an intersection between the axis H-H and the axis V-V, and is a point that becomes an origin of three-dimensional coordinates to be acquired by the surveying apparatus <NUM>.

When the image projecting unit <NUM> is driven by the projection control unit <NUM>, the light irradiating device <NUM> is driven, and projection light M is emitted and enters the display element <NUM>. The display element <NUM> forms an image as a projection image <NUM>. Next, through the projector lens <NUM>, the image as the projection image <NUM> is projected onto a surface of the measuring object as a projection target.

The positional relationship between the distance-measuring unit <NUM> and the image projecting unit <NUM> does not necessarily have to be arranged so that they are opposed to each other on a common axis. What is required is that the positional relationship between the distance-measuring unit <NUM> and the image projecting unit <NUM> is known, and the projection image <NUM> and the measurement data can be converted into data in the same coordinate space.

The operation unit <NUM> is realized by any of, or a combination of any of all kinds of devices capable of receiving an input from a user and transmitting information related to the input to the control arithmetic unit <NUM>. For example, the operation unit <NUM> includes hardware input means such as buttons, software input means displayed on the display unit <NUM> such as a touch panel display, and input means such as a remote controller.

The control arithmetic unit <NUM> executes functions and/or methods realized by codes or instructions included in various programs stored in the storage unit <NUM>. The control arithmetic unit <NUM> may include, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit) microprocessor, and an ASIC (Application Specific Integrated Circuit), etc., and realize various processings disclosed in this specification by a logic circuit and a dedicated circuit formed in an integrated circuit, etc..

The control arithmetic unit <NUM> includes, as functional units, the survey unit <NUM>, the projection image generating unit <NUM>, and the projection control unit <NUM>.

The survey unit <NUM> performs a survey by the surveying apparatus <NUM> and calculates coordinates of the irradiation point of the distance-measuring light L, that is, the measurement point. Specifically, by controlling the rotation driving unit <NUM>, the telescope 4c collimates the measuring object, and by the distance-measuring unit <NUM> and the angle-measuring unit <NUM>, a horizontal angle, a vertical angle, and a distance between the surveying apparatus <NUM> and (the irradiation point on) the measuring object are detected. In addition, the survey unit <NUM> calculates coordinates of the measurement point with respect to an instrument center O set as a center based on the acquired horizontal angle, vertical angle, and distance. The coordinates of the measurement point calculated by the survey unit <NUM> are stored as measurement data in the storage unit <NUM>.

The projection image generating unit <NUM> calculates a three-dimensional shape of the measuring object based on the measurement data acquired by the survey unit <NUM> and is stored in the storage unit <NUM>. Next, this three-dimensional shape data is read by three-dimensional computer graphics, and distortion correction for projecting the measurement data as a visually confirmable image on a screen corresponding to the surface shape of the measuring object, is performed to generate the projection image <NUM>.

In the example illustrated in <FIG>, as a visually confirmable image, an image displaying measurement points P<NUM> to P<NUM> and measurement points P<NUM> to P<NUM> as circular points is illustrated. As a distortion correction method, for example, spline warp correction and pin warp correction, etc., can be applied. Shapes and colors of the measurement points in the generated image may be changeable.

The projection control unit <NUM> drives the light irradiating device <NUM> to emit projection light M, and causes the projection light M to enter the display element <NUM>. The projection control unit <NUM> performs a control to form an image as the projection image <NUM> by the projection light M reflected by or transmitted through the display element <NUM>. Accordingly, the image as the projection image <NUM> is projected onto the surface of the measuring object as a projection target through the projector lens <NUM>.

The projection control unit <NUM> directs the image projecting unit <NUM> toward the projection direction (measuring object) by controlling the rotation driving unit <NUM>.

In addition, the projection control unit <NUM> performs zooming and focusing of the projection image <NUM> by driving the lens driving unit. In focusing, for example, the lens driving unit is controlled based on the measurement data so that a portion where the measurement points are linearly arranged and dense is set as a focal position. Alternatively, it is also possible that a user can designate a plane as a reference, and the lens driving unit is controlled so that the focal position is set on the plane.

Next, operation of the surveying apparatus <NUM> will be described. <FIG> is a flowchart of operation of the surveying apparatus <NUM> in use. The on-site work illustrated in <FIG> is described.

The surveying apparatus <NUM> is installed at a known point. When operation of the surveying apparatus is started, in Step S101, the survey unit <NUM> collimates a measuring object S1 by driving the distance-measuring unit <NUM> and the angle-measuring unit <NUM>, and measures a distance and an angle to a measurement point on the measuring object S1.

Next, in Step S102, the survey unit <NUM> calculates three-dimensional coordinates of the measurement point from the results of the distance and angle measurements. The acquired three-dimensional coordinates of the measurement point are stored as measurement data in the storage unit <NUM>.

Next, in Step S103, the survey unit <NUM> displays a screen for confirming whether to continue the measurement on the display unit <NUM>, and according to a user's selection, continuation (Yes) or end (No) of the measurement is selected.

When the measurement is continued (Yes), the processing returns to Step S101, and the survey unit <NUM> repeats Steps S101 to S103 to measure another measurement point.

On the other hand, when the measurement is ended (No), the processing shifts to Step S104. In Step S104, the projection image generating unit <NUM> displays a screen for confirming whether to project the image on the display unit <NUM>, and according to a user's selection, it is selected to project the image (Yes) or not to project the image (No).

Here, when it is selected not to project the image (No), the control arithmetic unit <NUM> ends the processing. On the other hand, when it is selected to project the image (Yes), in Step S105, the projection image generating unit <NUM> generates the projection image <NUM> based on the measurement data stored in the storage unit <NUM>.

Next, in Step S106, the projection control unit <NUM> directs the image projecting unit <NUM> (projector lens <NUM>) toward the projection direction, that is, the measuring object S1 direction in a real space by driving the rotation driving unit <NUM>.

Steps S105 and S106 do not necessarily have to be performed in this order. That is, when a user desires to project measurement data of a specific portion (for example, the measuring object S1 in <FIG>) in a real space, it is also possible that after image projection is selected in Step S104, in Step S106, the projector lens <NUM> is directed toward the measuring object S1 by driving the rotation driving unit <NUM>. In this case, by executing Step S105 next, the projection image <NUM> is generated based on the measurement data of the portion of the measuring object S1 in the image projecting unit <NUM>.

Next, in Step S107, the projection control unit <NUM> controls the image projecting unit <NUM> to project the projection image <NUM> onto the measuring object S1 (<FIG>). In <FIG>, the projection image <NUM> displays the measurement points P<NUM> to P<NUM> and P<NUM> to P<NUM> as circular points arranged at even intervals vertically and horizontally on a surface of the three-dimensional structure S1. Here, a measurement point P<NUM> not displayed (illustrated with a dashed line) is a point that has not been measured for some reason. The measuring object S1 is simply schematically illustrated, and its shape is not particularly restricted.

Next, in Step S108, the projection control unit <NUM> stands by while confirming whether the end of projection is instructed, and when the end of projection is instructed (No), ends the processing.

The measurement in Steps S101 to S103 and the image projection in Steps S104 to S108 do not necessarily have to be performed as a series of operations, and may be performed as separate operations.

<FIG> is a view illustrating another usage state of the surveying apparatus <NUM>. <FIG> illustrates a situation where staking points P<NUM> to P<NUM> are being set.

In the case of <FIG>, a user U uses a remote catcher <NUM> including a fan beam transmitter 7a that transmits a fan beam and a prism 7b. The surveying apparatus <NUM> further includes a fan beam detector and an automatic tracking unit that automatically tracks the prism although not illustrated, and acquires three-dimensional coordinates of a staking point by measuring a distance and an angle to the prism vertically held on the staking point.

In the staking point setting work, as in a conventional manner, the user U holding the remote catcher <NUM> moves to each staking point and performs staking. Then, the operations of Steps S104 to S108 are performed, and the projection image <NUM> is projected onto a staking point setting region as a measuring object. Thus, the surveying apparatus <NUM> can also be used for confirming the staking points after staking.

In the present embodiment, the surveying apparatus <NUM> is provided with the image projecting unit <NUM> so as to project measurement data onto a measuring object in a real space, so that measurement results can be confirmed on-site without being carried back to an office and converted into display data. In particular, by projection onto the measuring object in a real space, a data measurement situation in the real space can be grasped intuitively.

For example, in the situation illustrated in <FIG>, only by confirming the projection image <NUM>, omission of the measurement of the measurement point P<NUM> can be immediately recognized. In the situation illustrated in <FIG>, whether a point at which staking has been actually performed matches a point measured as a staking point can be visually recognized.

In the present embodiment, by configuring the distance-measuring unit <NUM> and the image projecting unit <NUM> inside the telescope 4c so that their optical axes are opposed to each other on a common axis, the optical axis of the image projecting unit <NUM> can be matched with the optical axis of the distance-measuring unit <NUM> only by rotating the telescope 4c by <NUM>° in the vertical direction, so that complicated arithmetic processing is not required when generating the projection image in the projection image generating unit <NUM>, and the processing time can be shortened.

<FIG> is an external general view illustrating a state where a surveying apparatus <NUM> according to a second embodiment is projecting a projection image 6a. <FIG> is a configuration block diagram of the surveying apparatus <NUM>, and <FIG> is a schematic view describing configurations of the distance-measuring unit <NUM> and the image projecting unit <NUM> disposed in a light projecting unit 204c.

In the present embodiment, the surveying apparatus <NUM> is a so-called three-dimensional laser scanner. The surveying apparatus <NUM> and the surveying apparatus <NUM> have a common configuration except for the following respects. First, in appearance, the surveying apparatus <NUM> includes the telescope 4c that rotates about the axis V-V in the recessed portion <NUM> of the bracket 4b, and on the other hand, the surveying apparatus <NUM> includes the light projecting unit 204c in a recessed portion <NUM> of a bracket portion 204b.

In addition, between the distance-measuring unit <NUM> and the image projecting unit <NUM> in <FIG>, instead of the double-sided mirror <NUM> fixed to the telescope 4c, a turning mirror <NUM> is provided. The turning mirror <NUM> is a double-sided mirror, and like the double-sided mirror <NUM>, the turning mirror <NUM> is configured so that emitting optical axes of the distance-measuring unit <NUM> and the image projecting unit <NUM> advance toward directions opposite to each other on the same axis.

In addition, the turning mirror <NUM> is connected to the vertical rotation driving unit <NUM> so that, by performing scanning around the axis V-V by setting the instrument center O as a center, scanning in the vertical direction with the distance-measuring light L can be performed. A light emitting element <NUM> emits a pulse laser light (pulsed light). In this way, the surveying apparatus <NUM> is configured to be capable of acquiring point cloud data of the entire circumference by scanning the entire circumference with the distance-measuring light L in the horizontal direction and the vertical direction.

When the image projecting unit <NUM> is driven, the turning mirror <NUM> does not rotate, and the turning mirror <NUM> and the image projecting unit <NUM> are fixed. The image projecting unit <NUM> may be configured to rotate integrally with the turning mirror <NUM> so as not to obstruct the optical path of the distance-measuring light L during scanning with the distance-measuring light L.

Functionally, as illustrated in <FIG>, instead of including the survey unit <NUM> and the projection image generating unit <NUM> in the control arithmetic unit <NUM> in the surveying apparatus <NUM>, the surveying apparatus <NUM> includes a point cloud data acquiring unit <NUM> and a projection image generating unit <NUM> in a control arithmetic unit <NUM>.

The point cloud data acquiring unit <NUM> scans a measurement range (up to <NUM>°) with the distance-measuring light L by driving the distance-measuring unit <NUM>, the angle-measuring unit <NUM>, and the rotation driving unit <NUM>, acquires three-dimensional point cloud data of the measurement range, and stores the three-dimensional point cloud data in the storage unit <NUM>.

Based on the point cloud data stored in the storage unit <NUM>, the projection image generating unit <NUM> generates a projection image 6a in the same manner as in the projection image generating unit <NUM>.

Operations of the surveying apparatus <NUM> and the surveying apparatus <NUM> in use are generally the same as in the flowchart of <FIG>, however, instead of measuring distances and angles to the measurement points provided on the measuring object S2 one by one and acquiring three-dimensional coordinates of each point in Steps S101 to S103, the surveying apparatus <NUM> acquires point cloud data as measurement data.

The projection image 6a illustrated in <FIG> displays the respective points of point cloud data as circular points. Even in this case where the surveying apparatus <NUM> is a 3D laser scanner, the same effect as that of the first embodiment can be obtained in which measurement results can be confirmed on-site without being carried back to an office and converted into display data. In the projection image 6a in <FIG>, omission of a point cloud is found in a lower right portion in a front view of the measuring object S2. This may occur due to temporary presence of an obstacle such as a vehicle between the measuring object S2 and the surveying apparatus <NUM> at the time of the measurement. In this way, a user can intuitively recognize a point cloud data acquisition omitted portion (acquiring situation).

In this example, the projection image generating unit <NUM> calculates a three-dimensional shape of the measuring object S3 based on the measurement data (point cloud data) stored in the storage unit <NUM>. Then, this three-dimensional shape data is read by three-dimensional computer graphics, and the surface of the measuring object is obtained.

An image that displays distances between the surface and the respective points in a direction orthogonal to the surface in a pattern like a so-called heat map by using different colors for each of predetermined ranges (for example, ranges of <NUM> to <NUM>, <NUM> to <NUM>. , etc.) is generated. For example, in <FIG>, around the center of the surface of the measuring object S3, a portion protruding by <NUM> is illustrated.

By projecting this projection image 6b onto the measuring object S3, the user can easily and intuitively recognize irregularities on the surface of the measuring object S3. In this case, even irregularities invisible to the naked eye are conspicuously displayed, and this is advantageous.

Alternatively, the same effect can be obtained even when the projection image generating unit <NUM> is configured to generate an image that displays irregularities on the surface of the measuring object S3 in a recognizable manner like a so-called depth map by using different colors for each of predetermined ranges corresponding to distances from the instrument center to the respective points.

(<NUM>) <FIG> illustrates a projection image 6c according to another example, generated by the projection image generating unit <NUM>. In the projection image 6c, a surface of a measuring object S4 is divided into grids (meshes) at predetermined intervals, and the respective squares are displayed in colors different according to levels of point cloud density in the square regions.

In this example, based on the measurement data (point cloud data) stored in the storage unit <NUM>, the projection image generating unit <NUM> calculates a three-dimensional shape of the measuring object S4. Then, this three-dimensional shape data is read by three-dimensional computer graphics, and the surface of the measuring object S4 is obtained.

Then, the surface of the measuring object is divided into grids at predetermined intervals, and from the measurement data, point cloud densities in the respective squares are calculated and classified into <NUM> levels including level <NUM> (Lv. <NUM>) set to <NUM> points or more/m<NUM>, level <NUM> (Lv. <NUM>) set to <NUM> to <NUM> points/m<NUM>, and level <NUM> (Lv. <NUM>) set to less than <NUM> points/m<NUM>, and the projection image 6c displayed in colors different according to the levels of point cloud density in the squares is generated.

By projecting this projection image 6c, a user can visually and intuitively recognize a situation such as which portion meets required density in the point cloud data of the measuring object S4.

Modifications of the projection image are not limited to these, and for example, the levels of point cloud density may be displayed like a heat map as with the projection image 6b. Alternatively, irregularities from the surface may be displayed in meshes.

The above-described modifications of the projection images 6b and 6c are applicable not only to the surveying apparatus <NUM> but also to the surveying apparatus <NUM>.

<FIG> is a configuration block diagram of a surveying apparatus <NUM> according to a third embodiment, and <FIG> is an external general view illustrating a state where the surveying apparatus <NUM> is projecting a projection image 6d, and illustrates a situation of measurement of the same site as in <FIG>.

The surveying apparatus <NUM> is a total station having substantially the same configuration as that of the surveying apparatus <NUM>, but is different in that a storage unit <NUM> has design data <NUM> of the measuring object S1, and the control arithmetic unit <NUM> includes a projection image generating unit <NUM> in place of the projection image generating unit <NUM>.

The projection image generating unit <NUM> is configured to calculate a difference between the design data <NUM> and the measurement data when generating the projection image 6d, and generate an image displaying the difference from the measurement data in a recognizable manner.

For example, when there is a difference between the measurement data and the design data <NUM> as in the case where the design data <NUM> includes information on the measurement points P<NUM> to P<NUM>, the measurement data of the point P<NUM> moves rightward from the point P<NUM> illustrated with a dashed line on the design data <NUM>, and measurement data of the point P<NUM> has not been acquired, the deviating portion may be conspicuously displayed by being changed in color or shape as illustrated in <FIG>.

With this configuration, a user can intuitively grasp the difference from the design data <NUM>. The same modification can be applied to the surveying apparatus of the second embodiment, and can be applied in combination with the above-described modification of the projection image.

Claim 1:
A surveying apparatus (<NUM>) comprising:
a distance-measuring unit (<NUM>) configured to transmit distance-measuring light and measure a distance to a measurement point by receiving reflected distance-measuring light reflected by a measuring object;
an angle-measuring unit (<NUM>) configured to measure an angle to the measurement point by detecting an angle of the distance-measuring light;
a control arithmetic unit (<NUM>) including
a survey unit configured to acquire three-dimensional coordinates of the measurement point as measurement data by performing distance and angle measurements by controlling the distance-measuring unit and the angle-measuring unit,
a projection image generating unit (<NUM>) configured to generate a projection image for displaying the measurement data on a surface of the measuring object by acquiring a three-dimensional shape of the measuring object based on the measurement data, and
a projection control unit (<NUM>) configured to control projection of the projection image onto the measuring object; and
an image projecting unit (<NUM>) including a display element configured to form an image as the projection image, a light irradiating device configured to cause projection light to enter the display element, and a projector lens configured to project the projection image emitted from the display element onto the measuring object, wherein
the distance-measuring light is pulsed light, and the surveying apparatus (<NUM>) is a laser scanner configured to acquire three-dimensional point cloud data of the measuring object by scanning with the distance-measuring light in the vertical direction and the horizontal direction,
characterized in that:
the projection image generating unit generates (<NUM>), as the projection image, an image displaying levels of point cloud density of the three-dimensional point cloud data in a recognizable manner.