JP2003344046A - Light wave range finder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a light wave range finder for reducing ranging time until a ranging result is displayed after ranging start is instructed. <P>SOLUTION: The light wave range finder comprises: a light wave distance meter 20; a ND filter 29 for transmitting light being provide on the emission light path of the light transmission system in the light wave distance meter 20; and an AF detection unit 50. In the light wave range finder, a control circuit 40 adjusts the positions of the ND filter 29 for transmitting light and the ND filter 33 for receiving light from AF information obtained by an AF operation when the AF operation is completed. Then, distance measurement operation is started by the light wave distance meter 20 while the position adjustment is completed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical distance measuring device (EDM) having a function of adjusting the amount of distance measuring light.

[0002]

2. Description of the Related Art The measurement of distances by various surveying instruments is generally carried out by measuring the phase difference between the transmitted light and the reflected light projected onto the object to be measured, the initial phase of the internal reference light, or the transmitted and reflected light. It is performed by an optical wave rangefinder (EDM) that calculates a distance from a time difference.

In general, a light-wave distance measuring instrument sends a distance measuring light to an object to be measured via a light transmitting / receiving mirror located behind the objective lens of the collimation telescope and located at the center of the optical axis. It has a light emitting element and a light receiving element for receiving the reflected light that cannot be reflected by the light transmitting and receiving mirror among the reflected light from the measurement object. In this conventional type, the distance measuring light amount (light sending amount) is set so that sufficient measurement accuracy can be obtained even for a long-distance or low reflectance measurement object, while the light receiving side reduces the density unevenly. An optical filter (ND filter) is provided and this N
By adjusting the position of the D filter, it is possible to measure the distance from a long distance to a short distance. In addition, depending on the measurement conditions, the reflection of sunlight on the measurement object may be extremely large and may be affected as noise. Therefore, there is an ND filter provided on the light transmitting side. In this case, the positions of the ND filters on the light-receiving side and the light-transmitting side are adjusted to increase the light-transmitting amount and at the same time decrease the light-receiving amount.
The ratio is increased so that even such an object to be measured can be measured satisfactorily.

By the way, in an optical distance measuring instrument equipped with an ND filter, conventionally, the position of the ND filter is adjusted during the distance measuring operation. Specifically, for example, when the measurement start switch is turned on, the distance measurement light is emitted to detect the reflected light from the measurement object, and the ND filter is moved stepwise to determine the amount of reflected light from the measurement object. Is detected, and the measurement operation is started from the state where the ND filter is held at this detected position. If the position adjustment of the ND filter is performed during the distance measuring operation as described above, it takes too much time from the time when the measurement start switch is turned on until the measurement result is displayed, and a quick operation can be expected. could not. In particular, when performing non-prism measurement without using a prism, not only the reflected light is attenuated by the distance to the measurement object, but also by the color and reflection surface condition (reflectance or reflection angle) of the measurement object. Since the reflected light changes, the distance measurement time becomes longer than when measuring the prism.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a lightwave distance measuring device capable of shortening the distance measuring time from the start of the distance measuring instruction to the display of the distance measuring result. To do.

[0006]

SUMMARY OF THE INVENTION The present invention is a collimating telescope for collimating an object to be measured; a light sending system for sending distance measuring light to the object to be measured;
A light wave distance meter having a light receiving system for receiving the reflected light from the measurement object, and measuring the distance to the measurement object; focusing means for moving the focusing lens of the collimation telescope to the focusing position; distance measurement It is characterized in that it is provided with a light amount adjusting means arranged on the optical path for adjusting the distance measuring light amount; and a control means for operating the light amount adjusting means based on the focus information obtained during the focus operation.

Focusing information obtained during the focusing operation is preferably at least one of distance information, luminance information of the measuring object, and color information of the measuring object. The distance information can be obtained by converting the position information of the focus adjustment lens. Alternatively, it can be obtained from the defocus amount before the focus adjustment lens is moved to the in-focus position. By using any of the above distance information, luminance information of the measurement object, and color information of the measurement object, it is possible to properly adjust the distance measurement light amount without actually detecting the reflected light from the measurement object. You can

The light quantity adjusting means includes a non-uniform density filter arranged on the incident light path of the light receiving system, on the exit light path of the light sending system, or on both the incident light path of the light receiving system and the exit light path of the light sending system. It is preferable to adjust the amount of light by moving it.

The light-wave rangefinder may further include focus detection means for detecting the focus state of the collimation telescope. When the focus detecting means is provided, the focusing means is preferably an automatic focusing means for moving the focus adjusting lens to the focus position based on the focus state detected by the focus detecting means, and the control means is At the end of the automatic focusing operation of the automatic focusing means, it is preferable to operate the light amount adjusting means based on the focusing information obtained by the focusing operation. With this configuration, the position of the density nonuniformity filter is appropriately adjusted based on the focus information obtained during the automatic focusing operation, and the distance measurement by the optical distance meter is started in the state where the position adjustment is performed. It
Therefore, it is not necessary to adjust the position of the density non-uniformity filter during the distance measurement, and the time from the start of the distance measurement by the optical distance meter to the display of the distance measurement result can be shortened.

When the focus detecting means and the automatic focusing means are provided, the luminance information of the measuring object can be obtained by converting from the integration time of the integrating means (CCD) provided in the focus detecting means. it can. In addition, the color information of the measuring object is, for example, the integrating means (C
By providing an on-chip color filter in (CD), it can be detected from the output signal of the integrating means.

The focusing means can also be a manual focusing means for manually moving the focusing lens of the collimation telescope. When the manual focusing means is provided, the control means is
It is preferable to operate the light amount adjusting means based on the distance information before starting the operation of the optical distance meter. This distance information is obtained by converting the position information of the focus adjustment lens. Even with this configuration, since the distance measurement by the lightwave rangefinder is started in the state where the light amount is adjusted, it is not necessary to adjust the position of the density nonuniformity filter during the distance measurement,
It is possible to shorten the time from the start of the distance measurement by the optical distance meter to the display of the distance measurement result.

The control means calculates, for example, the amount of reflected light from the object to be measured and the SN ratio using the focusing information obtained during the automatic focusing operation of the automatic focusing means, and based on the calculated amount of reflected light and the SN ratio. Set the filter position that optimizes the distance measurement light amount. Then, it is preferable to operate the light amount adjusting means so as to move the density nonuniformity filters to the set filter positions. When the light quantity adjusting means is provided in both the light receiving system and the light sending system, the light quantity adjusting means of the light receiving system and the light sending system are independently operated so that the light receiving quantity and the light sending quantity are optimized.

Specifically, it is preferable that the nonuniform density filter is a rotatable arc-shaped ND filter, and the light transmittance is gradually changed along the rotating direction.

The focus detecting means may be a phase difference detecting method or a contrast detecting method.

[0015]

1 is a system connection diagram showing an embodiment of a lightwave distance measuring device according to the present invention. As shown in FIG. 1, the collimation telescope 10 provided in the present optical distance measuring instrument includes an objective lens 11, a focus adjustment lens 17, a Porro prism (upright optical system) 12, and a focus in order from the object side (front side). Plate 13,
And an eyepiece lens 14. On the focusing screen 13,
At the center thereof, a cross hairline (collimation line) 15 that serves as a marker for collimation is drawn. The focus adjustment lens 17 is movable along the optical axis direction. This focusing lens 17
By adjusting the position according to the distance of the measuring object 16, the image can be correctly formed on the surface of the focusing screen 13 on the objective lens 11 side. The user uses this focusing screen 1
The image on 3 is magnified and observed through the eyepiece lens 14.

Behind the objective lens 11 of the collimation telescope 10, a transmitting / receiving mirror 21 which is a constituent element of the optical distance meter 20.
And the wavelength selection filter 22 that reflects the distance measuring light and transmits the visible light are sequentially arranged. The light transmitting / receiving mirror 21 is a parallel plane mirror positioned on the optical axis of the objective lens 11, and the surface on the objective lens 11 side constitutes the light transmitting mirror 21a and the surface on the wavelength selection filter 22 side constitutes the light receiving mirror 21b. There is.

A light emitting element (LD; laser diode) 23 of the lightwave distance meter 20 emits distance measuring light of a specific wavelength. This distance measuring light is applied to the collimator lens 24 and the fixed mirror 25.
It is incident on the light transmitting mirror 21a via. Transmitting mirror 2
The distance measuring light that has entered the optical axis 1a travels on the optical axis of the objective lens 11.

The wavelength selection filter 22 is used for the measurement object 16
And a light-transmitting mirror 21a that is reflected by the objective lens 11 and transmitted.
The light receiving mirror 21 that further reflects the distance measuring light that cannot be emitted
It acts to return to b. The light receiving mirror 21b makes the reflected light incident on the incident end surface 26a of the light receiving fiber 26. Two
Reference numeral 7 is a holder for holding the light receiving fiber 26, and together with the transmitting / receiving mirror 21, by a fixing means (not shown),
It is fixed in the space behind the objective lens 11.

On the distance measuring optical path between the light emitting element 23 and the fixed mirror 25, a collimator lens 24, a switching mirror 28 and an ND filter 29 for light transmission are arranged in this order from the light emitting element 23 side. The switching mirror 28 includes the actuator 3
7, the distance measuring light from the light emitting element 23 is applied to the fixed mirror 25, or the incident end face 26a of the light receiving fiber 26 is provided.
Is to be directly applied to. ND for light transmission
The filter 29 is a neutral density filter for adjusting the amount of distance measuring light projected on the measurement object 16, and is axially supported by the actuator 36 in a state orthogonal to the distance measuring optical axis.
Sensor 35 provided near ND filter 29 for light transmission
Is for detecting the position of the ND filter 29 for light transmission. The sensor 35 and the actuators 36 and 37 are connected to the control circuit 40. In this embodiment, the ND for light transmission
The filter 29, the sensor 35, and the actuator 36 constitute a light amount adjusting means for transmitting light.

A condenser lens 32, a light receiving ND filter 33, and a bandpass filter 34 are arranged in this order between the light emitting end face 26b of the light receiving fiber 26 and the light receiving element 31. The light receiving element 31 includes a condenser lens 32 and a light receiving ND.
The reflected light from the measuring object 16 is received through the filter 33, and the photocurrent corresponding to the received light amount is output to the control circuit 40. The light receiving ND filter 33 is a neutral density filter that adjusts the amount of reflected light incident on the light receiving element 31, and is axially supported by the actuator 41 in a state orthogonal to the incident optical axis of the light receiving element 31. The sensor 38 provided near the light receiving ND filter 33 is for detecting the position of the light receiving ND filter 33. The sensor 38 and the actuator 41 are connected to the control circuit 40. In the present embodiment, the light receiving ND filter 33, the sensor 38, and the actuator 41 constitute a light receiving light amount adjusting unit.

The light transmitting ND filter 29 and the light receiving N
The D filters 33 have the same configuration. ND for light transmission
The filter 29 (ND filter 33 for receiving light) is shown in FIG.
As shown in (a), a single rotating disk 29a (33a) having a rotating axis parallel to the distance measuring optical axis, and the rotating disk 29a.
A circular arc-shaped ND filter 29b (33b) provided at a radial position g through which the distance measuring optical axis passes on a (33a), and a plurality of slits 29c (33c) provided along the outer circumference of the circular arc-shaped ND filter 29b (33b). Consists of. The hatched portion in FIG. 2A indicates that the transmittance is 0%. The arc-shaped ND filter 29b (33b) is shown in FIG.
As shown in (b), the light transmittance gradually changes along the circumferential direction A. In this embodiment, the rotating disk 29a (33) is moved by the circumferential direction A and the actuator 36 (41).
The light amount of the distance measuring light is adjusted by adjusting the position (rotation angle) of the arc-shaped ND filter 29b (33b) which is located in the distance measuring optical path and is aligned with the direction B in which a) is rotated. it can. The slit 29c (33c) is for detecting the position of the ND filter 29 for light transmission (ND filter 33 for light reception). That is, when the rotary disc 29a (33a) rotates and the slit 29c (33c) passes the sensor 35 (38), a pulse signal is output from the sensor 35 (38),
The control circuit 40 detects the position of the light-transmitting ND filter 29 (light-receiving ND filter 33) based on this output. Although not described in detail, the slits 29c (33c) may be an incremental type in which the origin position is provided or an absolute type.

As is well known, the above-mentioned optical distance meter 20 is
The control circuit 40 drives the switching mirror 28 via the actuator 37 to create a state in which the distance measuring light is applied to the fixed mirror 25 and a state in which it is directly applied to the incident end face 26a of the light receiving fiber 26. As described above, the distance measuring light applied to the fixed mirror 25 is projected onto the measuring object 16 via the light transmitting mirror 21a and the objective lens 11, and the reflected light is reflected by the objective lens 11, the wavelength selection filter 22, and the wavelength selecting filter 22. The light enters the incident end face 26a via the light receiving mirror 21b. Then, the reflected light reflected by the measurement object 16 and incident on the incident end face 26a,
The internal reference light directly given to the incident end face 26a via the switching mirror 28 is received by the light receiving element 31, the control circuit 40 detects the phase difference or time difference between the reflected light and the internal reference light, and the measurement object 16 is reached. And calculate the distance of
To display. A distance measurement calculation based on a phase difference or a time difference between the reflected light and the internal reference light is well known.

The control circuit 40 further includes a lens position detection sensor 18 for detecting the position of the focus adjustment lens 17, the display section 42, a lens drive mechanism 43 for moving the focus adjustment lens 17, an operation section 44 and an AF detection unit. 50 is connected. In addition to the distance measurement result, the display unit 42 displays A
Information related to surveying such as F status and mode information is displayed. The operation unit 44 includes an AF start switch 45 for starting an AF operation and a distance measurement start switch 4 for starting a distance measurement operation.
6. Operation switches such as a mode changeover switch 47 for switching between the AF mode and the MF mode are provided.

An optical path splitting surface is formed on the Porro prism 12, and an AF detection unit (focus detection means) 50 is arranged on this split optical path. The AF detection unit 50 detects the focus state of the focus detection surface 51 that is optically equivalent to the focusing screen 13, that is, the defocus amount of the front focus, the rear focus, and the like. FIG. 3 shows a conceptual diagram of the AF detection unit 50.

Objective lens 1 which forms an image on the focus detection surface 51
The object image of 1 is formed by a condenser lens 52 and a pair of separator lenses (imaging lenses) 53 arranged apart from each other by a base line length.
And the pair of divided images is a pair of C
The image is re-formed on the CD line sensor 54. Line sensor 5
4 has a large number of photoelectric conversion elements, and each photoelectric conversion element photoelectrically converts the received object image to integrate (accumulate) the photoelectrically converted charges, and outputs the integrated charges to the control circuit 40 as AF sensor data. To do. Although not shown, the line sensor 54 is provided with an on-chip color filter for detecting color information of the measuring object 16.

The control circuit 40 performs a predetermined defocus calculation based on the pair of AF sensor data, and operates the lens driving mechanism 43 based on the calculated defocus amount. The control circuit 40 then controls the lens position detection sensor 18
The focus adjustment lens 17 is moved to the in-focus position while detecting the position of the focus adjustment lens 17 on the basis of the output of.
Such defocus calculation is well known to those skilled in the art. In the present embodiment, the lens position detection sensor 18, the lens driving mechanism 43, and the control circuit 40 constitute an automatic focusing means, and the lens driving mechanism 43 manually moves the focus adjustment lens 17 by manual focusing means ( It also functions as an MF means).

The present lightwave distance measuring device having the above-mentioned configuration is characterized in that the amount of distance measuring light is adjusted based on focusing information. That is, when the AF mode is selected as the focus adjustment mode, the position adjustment of the light-transmitting and light-receiving ND filters 29 and 33 is performed by the AF operation at the end of the AF operation (automatic focusing operation). Do it based on information. On the other hand, when the MF mode is selected as the focus adjustment mode, the position adjustment of the light-transmitting and light-receiving ND filters 29 and 33 is performed.
Before starting the operation of the optical distance meter, it is performed based on the focus information obtained during the manual focus operation. If the positions of the light-transmitting and light-receiving ND filters 29 and 33 are adjusted in advance in this way, it is not necessary to perform the position adjusting operation at the time of distance measurement (or only fine adjustment is necessary), and therefore the distance measurement start switch. It is possible to shorten the time from when the switch 46 is turned on until the distance measurement result is displayed on the display unit 42. As a result, quick distance measurement work can be performed.

Focusing information obtained during the AF operation is distance information, luminance information and color information of the measuring object 16, and focusing information obtained during the manual focusing operation is distance information. It is preferable that the focus information used for the light amount adjustment operation includes at least one or more of the distance information, the luminance information of the measurement target 16, and the color information of the measurement target 16. The distance information is obtained by converting the position information of the focus adjustment lens 17 or the defocus amount calculated during the AF operation. The brightness information of the measurement object 16 is obtained by converting the integration time of the CCD line sensor 54 included in the AF detection unit 50. The color information of the measuring object 16 is obtained from the AF sensor data output through an on-chip color filter (not shown) provided in the CCD line sensor 54. By using these pieces of information, the filter position can be set so that the distance measuring light amount with respect to the measurement object 16 and the incident light amount of the light receiving element 31 are optimized, and the light emitting element 2
The positions of the light-transmitting and light-receiving ND filters 29 and 33 can be appropriately adjusted without actually causing 3 to emit light.

The position adjusting operation of the light-transmitting and light-receiving ND filters 29 and 33 will be described below in more detail with reference to FIG. FIG. 4 is a flowchart relating to the main processing of the present lightwave distance measuring device. This main processing including the filter position adjusting operation is controlled by the control circuit 40 and is started when the power of the present optical distance measuring instrument is turned on.

When the main processing is started, first, the focus adjustment mode is set to A based on the switch state of the mode changeover switch 47.
It is checked whether or not the F mode is set (S1
1). If the AF mode is set (S11;
Y), and waits until the AF start switch 45 is turned on (S13; N). When the AF start switch 45 is turned on (S13; Y), the AF detection unit 50 is activated to execute the AF operation (S15). When the AF operation is completed, the distance information obtained by the AF operation and the measurement target 16
Of the focus information such as the brightness information and the color information of the measurement object 16 (S17), and the distance information stored in S17, the brightness information of the measurement object 16 and the color information of the measurement object 16 are used in S21. Arithmetic processing is performed (S21).

On the other hand, when the MF mode is set (S11; N), the position information of the focus adjustment lens 17 is detected by the lens position detection sensor 18 and stored in the memory (S1).
8) Then, it is checked whether or not the position information of the focus adjustment lens 17 has changed since the previous detection (S19). When executing S19 for the first time after entering the main process, S1
The position information stored in 8 is compared with the stored data of the previous lens position. If it is determined that there is no change in S19, the process directly proceeds to S35 (S19; N). If it is determined that there is a change in S19, the positional information of the focus adjustment lens 17 stored in S18 is converted to obtain distance information, and the arithmetic processing of S21 is performed using the obtained distance information (S1).
9; Y, S21).

In the calculation processing of S21, S17 or S18
The amount of reflected light and the SN ratio of the measuring object 16 are calculated using the focus information stored in the memory, and the optimum value of the amount of distance measuring light to the measuring object 16 and the light receiving element 31 are calculated from the calculated reflected light amount and the SN ratio. The optimum value of the incident light amount of is calculated. Then, the light-transmitting and light-receiving ND filters 29, 3 for obtaining respective optimum values
3 positions (optimal filter positions) are respectively determined, and the ND filters 2 for light transmission and light reception up to the optimum filter positions
The movement amounts of 9 and 33 are calculated respectively. In the present embodiment, the amount of movement of the light-transmitting and light-receiving ND filters 29, 33 is converted into the number of pulses output from the sensors 35, 38 for calculation.

Subsequently, the actuators 36 and 41 are driven to start the movement of the light transmitting and light receiving ND filters 29 and 33 (S23). When the movement of the light-transmitting ND filter 29 is started, a pulse signal is output from the sensor 35 every time the light-transmitting ND filter 29 moves by a predetermined amount. Similarly, when the movement of the light receiving ND filter 33 is started, each time the light receiving ND filter 33 moves by a predetermined amount,
A pulse signal is output from the sensor 38. Control circuit 40
Can count the number of pulses output from the sensors 35 and 38, respectively, to detect the current position and the amount of movement of the light-transmitting and light-receiving ND filters 29 and 33.

Light transmitting and light receiving ND filters 29, 33
After the start of the movement of No. 3, it is checked whether or not the light-transmitting ND filter 29 has reached the optimum filter position determined in S21 based on the number of pulses output from the sensor 35 (S2
5) If it reaches, the actuator 36 is stopped to stop the ND filter 29 for light transmission (S25; Y, S2).
7). On the other hand, if the light-transmitting ND filter 29 has not reached the optimum filter position, S27 is skipped and the movement of the light-transmitting ND filter 29 is continued (S25; N). Subsequently, in S29, based on the number of pulses output from the sensor 38, it is checked whether or not the light receiving ND filter 33 has reached the optimum filter position defined in S21. N for receiving light
If the D filter 33 has reached the optimum filter position, the actuator 41 is stopped and the light receiving ND filter 33
Is stopped (S29; Y, S31). On the other hand, N for receiving light
If the D filter 33 has not reached the optimum filter position, S31 is skipped and the movement of the light receiving ND filter 33 is continued (S29; N). Then, it is checked whether or not both the light-transmitting and light-receiving ND filters 29 and 33 have reached the optimum filter positions (S33), and if either of them has not been reached, the process returns to S25 (S33; N).
When both the light-transmitting and light-receiving ND filters 29 and 33 reach the optimum filter positions, the process proceeds to S35 (S33;
Y)

In S35, the switch state of the distance measurement start switch 46 is checked. If the distance measurement start switch 46 is not turned on (S35; N), it is checked whether the AF mode is set as the focus adjustment mode (S).
37). If the AF mode is set, the process returns to S35 and waits until the distance measurement start switch 46 is turned on (S37; Y). On the other hand, if the MF mode is set (S37; N), it is checked whether or not a predetermined time has passed since the position information of the focus adjustment lens 17 was stored (S).
39). If the predetermined time has not elapsed, the process returns to S37,
Standby until the distance measurement start switch 46 is turned on (S3
9; N). On the other hand, if the predetermined time has elapsed, S1
Return to 8 (S39; Y). Accordingly, in the MF mode, the position adjustment of the light-transmitting and light-receiving ND filters 29 and 33 is periodically performed until the AF start switch 45 is turned on.

When the distance measurement start switch 46 is turned on (S35; Y), the distance measurement by the lightwave distance meter 20 is executed (S41), the obtained distance measurement result is displayed on the display unit 42, and the process returns to S11. (S43).

In the above main processing, when the distance measurement start switch 46 is turned on, the distance measurement by the lightwave distance meter 20 is started with the position adjustment of the light-transmitting and light-receiving ND filters 29, 33 completed. To be done. Therefore, the time from when the distance measurement start switch 46 is turned on until the distance measurement result is displayed is shortened by a time corresponding to the time for adjusting the positions of the light-transmitting and light-receiving ND filters 29 and 33. Improves the responsiveness. In particular, in non-prism measurement without using a prism, the attenuation of reflected light from the measurement object 16 is larger than that in prism measurement, and the ND filter for light transmission and light reception is used in the state where the distance measuring light is emitted as in the conventional case. Since the adjustment of the positions of 29 and 33 requires more time than the prism measurement, the distance measurement time can be more effectively shortened.

In the present embodiment, after the distance measurement start switch 46 is turned on, the ND filters 29 for transmitting and receiving light,
Although the position adjustment of 33 is not performed, the light emitting element 23 is turned on after the distance measurement start switch 46 is turned on in order to more strictly set the distance measuring light amount to the measurement object 16 and the incident light amount to the light receiving element 31. The positions of the light-transmitting and light-receiving ND filters 29 and 33 may be finely adjusted with the distance measuring light emitted. Even when performing this fine adjustment, the distance measurement start switch 4
Since the positions of the light-transmitting and light-receiving ND filters 29 and 33 are adjusted based on the focus information before the switch 6 is turned on, the distance measuring time can be shortened as compared with the conventional case.

Further, in the present embodiment, the distance information, the luminance information of the measuring object 16 and the color information of the measuring object 16 are used as the focusing information used for the light amount adjusting operation in the AF mode. If at least one of the information is used, the optimum positions of the light-transmitting and light-receiving ND filters 29 and 33 can be appropriately set.

In this embodiment, the ND filter 29 for transmitting light is used.
And the ND filter 33 for receiving light have the same configuration,
It is also possible to use ND filters of different configurations.

In this embodiment, the AF detection unit 50 of the phase difference detection method is used, but it goes without saying that another AF method such as the contrast method may be used.

In this embodiment, the light amount adjusting means is provided on both the exit optical path of the light transmitting system and the incident optical path of the light receiving system, but the light amount adjusting means may be provided on only one of them.

[0043]

According to the present invention, it is possible to obtain an optical distance measuring device capable of shortening the distance measuring time from the start of the distance measuring instruction to the display of the distance measuring result.

[Brief description of drawings]

FIG. 1 is a system connection diagram showing an embodiment of a lightwave distance measuring device having an AF function according to the present invention.

FIG. 2A is a diagram illustrating an ND filter for transmitting light of FIG.
It is a top view which shows a filter. (B) It is a graph which shows the light transmittance of the ND filter for light transmission (ND filter for light reception) of (a).

FIG. 3 is a view taken in the direction of arrow I in FIG. 1, and is a conceptual diagram of an AF detection unit (phase difference type focus detection means).

FIG. 4 is a flowchart of main processing of the optical distance measuring device of FIG.

[Explanation of symbols]

10 Collimation telescope 11 Objective lens 12 Porro prism 14 eyepiece 16 Object to be measured 17 Focusing lens 18 Lens position detection sensor 20 Lightwave rangefinder 23 Light emitting element 29 ND filter for light transmission (uniform density filter) 31 Light receiving element 33 ND filter for receiving light (uniform density filter) 35 38 sensor 36 37 41 Actuator 40 control circuit 42 Display 43 Lens drive mechanism 44 Operation part 45 AF start switch 46 Distance measurement start switch 47 mode switch 50 AF detection unit (focus detection means)

Claims (10)

[Claims] 1. A collimation telescope for collimating a measurement target; a light transmission system for transmitting distance measurement light to the measurement target, and a light receiving system for receiving reflected light from the measurement target. An optical distance meter for measuring the distance to the object to be measured; a focusing means for moving the focusing lens of the collimation telescope to a focusing position; a light quantity adjusting means arranged on the distance measuring optical path for adjusting the distance measuring light quantity; And a control means for operating the light amount adjusting means based on focusing information obtained during focusing operation. 2. The lightwave rangefinder according to claim 1, wherein the focusing information obtained during the focusing operation is one or more of distance information, luminance information of the measuring object, and color information of the measuring object. Lightwave rangefinder. 3. The lightwave distance measuring device according to claim 2, wherein the distance information is obtained by converting position information of the focus adjustment lens. 4. The light distance measuring device according to claim 1, wherein the light amount adjusting means is on an incident optical path of a light receiving system, on an outgoing optical path of a light transmitting system, or on a light receiving system. An optical distance measuring device that adjusts the distance measurement light amount by moving density nonuniformity filters arranged both on the incident light path and on the exit light path of the light transmission system. 5. The optical rangefinder according to claim 1, further comprising a focus detection unit that detects a focus state of the collimation telescope, wherein the focusing unit detects the detection state. Automatic focusing means for moving the focus adjusting lens to a focusing position based on the focused state, wherein the control means obtains the focusing operation at the end of the automatic focusing operation of the automatic focusing means. A lightwave distance measuring device that operates the light amount adjusting means based on focus information. 6. The lightwave distance measuring device according to claim 1, wherein the focusing means is a manual focusing means for manually moving the focus adjustment lens, and the control means. Before starting the operation of the lightwave rangefinder,
A lightwave distance measuring device that operates the light amount adjusting means based on distance information. 7. The lightwave rangefinder according to claim 1, wherein the control means calculates the reflected light amount and the SN ratio from the measurement object using the focus information, and the calculated reflected light amount and the SN ratio. From the above, a lightwave distance measuring device that sets a filter position that optimizes the distance measuring light amount and operates the light amount adjusting means to move the density nonuniformity filter to the filter position. 8. The lightwave distance measuring device according to claim 4, wherein the density nonuniformity filter is a rotatable arc-shaped ND filter, and the light transmittance gradually changes along the rotation direction. An optical wave rangefinder. 9. The lightwave distance measuring device according to claim 5, wherein the focus detecting means is a phase difference detecting focus detecting means. 10. The lightwave rangefinder according to claim 5,
The focus detection means is an optical distance measuring instrument which is a focus detection means of a contrast detection method.