JP2017078611A - Measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement device with which the uniformity of distance measurement accuracy in a direction of an object is enhanced.SOLUTION: The measurement device comprises: a mirror unit 142 in which an angle formed by an outgoing light from a light source and a reflection measurement light of the outgoing light oscillates centering round an oscillation axis 146 in a range from a maximum angle to a minimum angle; a light-receiving element 160 for receiving a reflected light 161 of the reflection measurement light from a measurement object via the mirror unit 142; and a light-receiving optical unit 150a located on a light-receiving optical axis linking the mirror unit 142 having a prescribed mirror width in a direction perpendicular to the oscillation axis 146 and the light-receiving element 160, the light-receiving optical unit 150a having a light shielding member 151 as a received light limiting unit for limiting the amount of transmitted light with a smaller limit width than the projected dimension in the direction of the light-receiving optical axis of the mirror width when the angle is a minimum angle.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a measuring apparatus for measuring a distance to an object.

  Conventionally, there is a measuring apparatus that emits laser light in a plurality of directions using a movable mirror and receives the laser light reflected by an object through the movable mirror (see, for example, Patent Document 1).

International Publication No. 2008/149851

  However, in the conventional measuring apparatus, the amount of reflected light from the object that reaches the light receiving element changes according to the direction of the movable mirror. As a result, the SN (Signal-Noise) ratio in the light receiving element changes depending on the direction of the object, thereby impairing the uniformity of distance measurement accuracy.

  Therefore, the present invention provides a measurement apparatus that improves the uniformity of distance measurement accuracy with respect to the direction of an object.

  In order to achieve the above object, a measuring apparatus according to one aspect of the present invention is configured so that an angle formed between light emitted from a light source and reflected measurement light of the emitted light is in a range from a minimum angle to a maximum angle with respect to an oscillation axis. A mirror portion that swings and has a predetermined mirror width in a direction perpendicular to the swing axis, a light receiving element that receives the reflected light of the measurement object of the reflected measurement light through the mirror portion, the mirror portion, A light receiving optical unit that is on a light receiving optical axis connecting to the light receiving element, and the light receiving optical unit is smaller than a projection size of the mirror width in the light receiving optical axis direction when the angle is the minimum angle. A received light amount limiting unit that limits the amount of transmitted light by the width is provided.

  Here, the projected dimension of the mirror width in the direction of the light receiving optical axis varies depending on the inclination of the mirror portion. Therefore, the amount of the reflected light received by the light receiving element varies depending on the projection size. The variation in the amount of received light hinders the uniformity of distance measurement accuracy according to the direction of the object.

  On the other hand, according to the configuration, since the amount of reflected light limited by the limit width reaches the light receiving element by the light receiving amount limiting unit, the maximum amount of the reflected light received by the light receiving element. Is suppressed. As a result, the variation in the amount of received light is reduced, and the uniformity of distance measurement accuracy with respect to the direction of the object is improved.

  The light receiving amount limiting unit may be a light shielding member having a light transmitting unit having the limiting width in a direction perpendicular to the swing axis.

  According to this configuration, the amount of the reflected light received by the light receiving element can be limited by the limit width by the light blocking member.

  The translucent part may have a height higher than the mirror part in the direction of the swing axis.

  According to the configuration, the reflected light reflected in the entire area of the height of the mirror part reaches the light receiving element through the light transmitting part, so that the height of the mirror part is not wasted. Further, since the height of the mirror portion viewed from the light receiving element is constant regardless of the inclination of the mirror portion, the amount of received light can be reduced without limiting the height of the reflected light reflected by the mirror portion. The effect of suppressing fluctuations is not impaired.

  The received light amount limiting unit is a lens having the limiting width in a direction perpendicular to the swing axis.

  According to this configuration, the amount of the reflected light received by the light receiving element can be limited by the limit width by the lens.

  Further, the lens has a height higher than that of the mirror part in the direction of the swing axis.

  According to the above configuration, the reflected light reflected over the entire height of the mirror portion reaches the light receiving element through the lens, so that the height of the mirror portion is not wasted. Further, since the height of the mirror portion viewed from the light receiving element is constant regardless of the inclination of the mirror portion, the amount of received light can be reduced without limiting the height of the reflected light reflected by the mirror portion. The effect of suppressing fluctuations is not impaired.

  The lens may condense the reflected light reflected by the mirror unit on the light receiving element.

  According to this configuration, the amount of the reflected light can be limited by the limit width, and the limited reflected light can be condensed on the light receiving element only by the condensing lens. This is useful for reducing the size and cost of the measuring device by reducing the number of parts.

  The light receiving optical unit may be disposed outside a region having the limit width in a direction orthogonal to the swing axis in the optical path of the reflected light incident on the mirror unit.

  According to this configuration, the light receiving optical unit is disposed on the optical path of the reflected light that passes through the reflected light that does not reach the light receiving element by the light receiving optical unit. As a result, the degree of freedom of arrangement of the light receiving optical unit is improved, which is useful for reducing the size of the measuring apparatus and improving the design.

  According to the measuring apparatus of the present invention, a measuring apparatus with improved uniformity of ranging accuracy according to the direction of the object can be obtained.

2 is a front view illustrating an example of a configuration of a measuring apparatus according to Embodiment 1. FIG. 3 is a cross-sectional view illustrating an example of a configuration of a light transmission region of the measurement apparatus according to Embodiment 1. FIG. 3 is a cross-sectional view illustrating an example of a configuration of a light receiving region of the measurement apparatus according to Embodiment 1. FIG. 3 is a block diagram illustrating an example of a functional configuration of the measurement apparatus according to Embodiment 1. FIG. 6 is a diagram schematically illustrating an example of a path of reflected light according to Embodiment 1. FIG. 6 is a diagram schematically illustrating an example of a path of reflected light according to Embodiment 1. FIG. 6 is a diagram schematically illustrating an example of a path of reflected light according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a projection shape of a light receiving mirror according to Embodiment 1. FIG. 3 is a conceptual diagram illustrating an example of a configuration of a light receiving optical unit according to Embodiment 1. FIG. 2 is a perspective view illustrating an example of an appearance of a light receiving optical unit according to Embodiment 1. FIG. 5 is a conceptual diagram illustrating an example of a configuration of a light receiving optical unit according to Embodiment 2. FIG. 6 is a perspective view illustrating an example of an appearance of a light receiving optical unit according to Embodiment 2. FIG. It is a conceptual diagram which shows an example of arrangement | positioning of the light reception optical part which concerns on a comparative example. 6 is a conceptual diagram illustrating an example of an arrangement of light receiving optical units according to Embodiment 3. FIG. 6 is a conceptual diagram illustrating an example of an arrangement of light receiving optical units according to Embodiment 3. FIG.

(Embodiment 1)
Hereinafter, embodiments will be specifically described with reference to the drawings.

  It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the like shown in the following embodiments are merely examples, and are not intended to limit the scope of the claims. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims are described as arbitrary constituent elements.

  Further, the following drawings are schematic diagrams and are not necessarily shown strictly. In each drawing, substantially the same configuration is denoted by the same reference numeral, and redundant description is omitted or simplified.

(Basic structure of measuring device)
The measurement apparatus according to the present embodiment is an apparatus that measures the distance to the objects 901 and 902 using light. Specifically, the measurement device emits measurement light that scans a target range outside the measurement device, and receives reflected light of the measurement light from an object within the target range. Measure the distance between the measuring device and the object.

  First, the basic structure of the measuring apparatus according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a front view of a measuring apparatus 100 according to the first embodiment.

  2 and 3 are cross-sectional views of the measuring apparatus 100 according to the first embodiment. Specifically, FIG. 2 is a cross-sectional view of the measuring apparatus 100 taken along the line II-II in FIG. 3 is a cross-sectional view of the measuring apparatus 100 taken along the line III-III in FIG. In the following drawings, invisible parts are indicated by broken lines.

  As shown in FIGS. 1 to 3, the measuring apparatus 100 includes a housing 110, a light shielding plate 119, a light source 120, a light transmission optical unit 130, a mirror unit 140, a light receiving optical unit 150, and a light receiving element 160. And comprising.

  The housing 110 stores the light source 120, the light transmitting optical unit 130, the mirror unit 140, the light receiving optical unit 150, and the light receiving element 160. The interior of the housing 110 is divided by a light shielding plate 119 into a light transmission region 113 through which light emitted from the light source 120 mainly passes and a light receiving region 114 through which light reflected mainly from the object passes. The housing 110 includes a light transmission window 111 for allowing the measurement light 121 to pass from the inside of the housing 110 to the outside of the housing 110, and a light receiving window for allowing the reflected light 161 to pass from the outside of the housing 110 to the housing 110. 112.

  The light source 120 emits light (for example, laser light). The light source 120 may be composed of a laser diode, for example. The light transmission optical unit 130 may include a collimating lens 131 and a light shielding member 132. The measurement light 121 from the light source 120 is converted into parallel light by the light transmission optical unit 130, reflected by the mirror unit 140, passes through the light transmission window 111, and is emitted to the outside of the housing 110. 902 is reached (see FIG. 2). The light transmission optical unit 130 may include a collimating lens 131 and a light shielding member 132.

  The reflected light 161 from the objects 901 and 902 reaches the light receiving element 160 via the mirror unit 140 and the light receiving optical unit 150. The light receiving element 160 includes, for example, a photodiode (PD) or an avalanche photodiode (APD) that is more sensitive than the photodiode. The light receiving optical unit 150 may include a light shielding member 151 and a condenser lens 152. The light receiving optical unit 150 will be described in detail later.

  The reflected light 161 from the objects 901 and 902 passes through the light receiving window 112, is reflected by the mirror unit 140, and reaches the light receiving element 160.

  The mirror unit 140 is a so-called scan mirror, and the angle formed between the light emitted from the light source 120 and the reflected measurement light of the emitted light is swung around the rocking shaft 146 in the range from the minimum angle to the maximum angle. The target range A is scanned with the measurement light 121 from the light source 120. The mirror unit 140 reflects the reflected light 161 from the objects 901 and 902 within the target range A toward the light receiving element 160.

  The mirror unit 140 may be, for example, a MEMS (Micro Electro Mechanical System) mirror that swings at least in the measurement range B around the swing shaft 146 by a swinger (not shown). The mirror unit 140 actually swings within a swing range wider than the measurement range B, and the region outside the measurement range B may be used for feedback control of the swing operation.

(Functional configuration of measuring device)
Next, the functional configuration of the measuring apparatus 100 will be described with reference to FIG.

  FIG. 4 is a block diagram illustrating a functional configuration of the measuring apparatus 100 according to the first embodiment. As shown in FIG. 4, the measuring apparatus 100 functionally includes a light source 120, a light transmitting optical unit 130, a mirror unit 140 including a light transmitting mirror 141 and a light receiving mirror 142, a light receiving optical unit 150, and a light receiving element. 160, a light source driving unit 170, a mirror driving unit 180, and a control unit 190.

  The light source driving unit 170 drives the light source 120. For example, the light source driving unit 170 causes the light source 120 to emit laser light in accordance with the modulation signal output from the control unit 190.

  The mirror driving unit 180 drives the mirror unit 140 (that is, the light transmission mirror 141 and the light receiving mirror 142). For example, the mirror driving unit 180 generates a driving current for driving the mirror unit 140 based on a driving signal from the control unit 190. The mirror drive unit 180 outputs the generated drive current to an oscillator not shown. As a result, the light transmission mirror 141 and the light receiving mirror 142 are integrally swung around the rocking shaft 146 by the rocker.

  The control unit 190 is a controller that controls the measurement apparatus 100. The control unit 190 includes, for example, a system LSI (Large Scale Integration), an IC (Integrated Circuit), or a microcontroller.

  Specifically, the control unit 190 controls the light source driving unit 170 and the mirror driving unit 180. For example, the control unit 190 outputs a modulation signal to the light source driving unit 170 and outputs a driving signal to the mirror driving unit 180.

  Furthermore, the control unit 190 calculates the distances from the measurement apparatus 100 to the objects 901 and 902 based on the phase difference between the light emitted from the light source 120 and the light received by the light receiving element 160. Specifically, the control unit 190 calculates the phase difference based on, for example, the modulation signal output to the light source driving unit 170 and the light reception signal input from the light receiving element 160. The control unit 190 calculates the time until the light emitted from the light source 120 reaches the light receiving element 160 using the calculated phase difference. And the control part 190 calculates the distance from the measuring apparatus 100 to the target object 901,902 by multiplying the light speed by 1/2 of the calculated time.

  In addition, the control unit 190 identifies the direction of the objects 901 and 902 relative to the measuring apparatus 100 from the inclination of the light transmission mirror 141. Here, the inclination is an angle value indicating a rotational position around the swing axis 146 of the light transmitting mirror 141 during swinging.

  The control unit 190 may detect the tilt of the light transmission mirror 141 based on a signal from a photodiode (not shown) installed at a predetermined position. The photodiode may be installed at a position where the measurement light 121 reflected by the light transmission mirror 141 is incident when the light transmission mirror 141 is rotated to a predetermined inclination outside the measurement range B.

(Light receiving operation of measuring device)
Next, details of the light receiving operation in the measuring apparatus 100 will be described with reference to FIGS. 5A, 5B, and 5C.

  5A, 5B, and 5C are diagrams schematically illustrating an example of a path of the reflected light 161 that reaches the light receiving element 160 when the light receiving mirror 142 is at the center, one end, and the other end of the measurement range, respectively. is there.

  In the following description, the following assumptions are made for the sake of brevity.

  That is, the inclination a, which means the position of the light receiving mirror 142 within the rocking range, is based on the stationary position of the non-rocking light transmitting mirror 141 and the clockwise direction is positive, and the rocking shaft 146 of the light receiving mirror 142 is positive. It is defined by the surrounding rotation angle. It is assumed that the stationary position is the center of the measurement range in which the light receiving mirror 142 swings. As a non-limiting specific example for illustration, the inclinations of the light receiving mirrors 142 at the center, one end, and the other end of the measurement range are a0 = 0 degree, a1 = -22.5 degrees (<0 degree), and a2 respectively. = + 22.5 degrees (> 0 degrees). The angle formed by the optical axis from the light receiving mirror 142 at the stationary position toward the light receiving element 160 and the normal line of the light receiving mirror 142 is defined as the mounting angle of the light receiving mirror 142, and is 45 degrees as a similar specific example.

  Under such a premise, the incident angle θ of the reflected light 161 that can reach the light receiving element 160 is an angle obtained by subtracting the inclination a of the light receiving mirror 142 from the mounting angle of the light receiving mirror 142. The incident angle θ is smaller as the inclination a is larger.

  Now, as shown in FIGS. 5A, 5B, and 5C, it is assumed that the reflected light 161 is a light beam 161a that spreads larger than the light receiving mirror 142. At this time, a part of the light beam 161b reflected by the light receiving mirror 142 of the light beam 161a reaches the light receiving element 160, but the remaining light beam 161c cannot reach the light receiving element 160 and is lost.

  The size of the light beam 161b reaching the light receiving element 160, that is, the amount of the reflected light 161 received by the light receiving element 160 is the appearance of the light receiving mirror 142 viewed from the light receiving element 160, that is, the light receiving element 160 and the light receiving element of the light receiving mirror 142. This is proportional to the size of the projected shape in the direction of the light receiving optical axis connecting the mirror 142.

  FIG. 6 is a diagram illustrating an example of the projected shape of the light receiving mirror 142. In FIG. 6, the projection shape 142a of the light receiving mirror 142 (corresponding to FIG. 5C) having the largest inclination in the measurement range is indicated by a thin line, and the light receiving mirror 142 having the smallest inclination in the measurement range (corresponding to FIG. 5B). ) Is indicated by a thick line.

  As shown in FIG. 6, the projected dimension of the mirror width (hereinafter referred to as the opening width), which is a dimension in the direction orthogonal to the swing axis 146 of the light receiving mirror 142, is minimum depending on the inclination of the light receiving mirror 142. It fluctuates between the value Wmin and the maximum value Wmax. The projected dimension (hereinafter referred to as height) of the light receiving mirror 142 in the direction parallel to the swing axis 146 is a constant value H.

  As a result, the amount of the reflected light 161 received by the light receiving element 160 varies between the amount of received light corresponding to the minimum opening width Wmin and the amount of received light corresponding to the maximum opening width Wmax according to the inclination of the light receiving mirror 142. fluctuate.

  As described above, in the background art section, it is pointed out that the amount of light reflected by the light receiving element 160 of the reflected light 161 from the object in the direction corresponding to the tilt varies according to the tilt of the light receiving mirror 142. This is a direct factor that impairs the uniformity of ranging accuracy with respect to the direction of the object.

(Details of light receiving optics)
Therefore, in the light receiving optical unit 150, the reflected light 161 reflected by the light receiving mirror 142 and traveling toward the light receiving element 160 is reflected light passing through a region having a predetermined limit width in a direction orthogonal to the swing axis 146. To reach. Here, the predetermined limit width is narrower than the maximum value within the measurement range of the opening width of the light receiving mirror 142.

  FIG. 7 is a conceptual diagram illustrating an example of a configuration of a light receiving optical unit 150 a as an example of the light receiving optical unit 150. The light receiving optical unit 150 a includes a light shielding member 151 having a substantially rectangular light transmitting unit 151 a and a condensing lens 152.

  FIG. 8 is a perspective view showing an example of the appearance of the light shielding member 151 and the condenser lens 152.

  The light shielding member 151 may be formed of, for example, a light shielding resin plate or a metal plate. The light transmitting portion 151a may be an opening provided in the light shielding member 151, and a light transmitting resin plate may be fitted into the opening. Further, the light shielding member 151 may be formed of a light transmissive resin plate, and light shielding coating may be applied to a region excluding the light transmissive portion 151a.

  The condensing lens 152 may be made of resin or glass.

  As shown in FIGS. 7 and 8, the light transmitting portion 151 a has a limited width w in a direction orthogonal to the swing shaft 146. The limit width w only needs to be smaller than the maximum value Wmax of the opening width of the light receiving mirror 142, and the specific size is not limited. For example, the limit width w may be equal to the minimum value Wmin of the opening width of the light receiving mirror 142.

  According to this configuration, the variation in the amount of the reflected light 161 received by the light receiving element 160 is limited to the variation between the amount of received light corresponding to the minimum value Wmin of the aperture width and the amount of received light corresponding to the limit width w. Therefore, the uniformity of ranging accuracy with respect to the direction of the object is improved.

  In particular, when the limit width w is equal to the minimum value Wmin of the aperture width, the received light amount of the reflected light 161 at the light receiving element 160 becomes a constant received light amount corresponding to the minimum value Wmin of the aperture width over the entire measurement range. Thereby, the variation in the amount of received light according to the inclination of the light receiving mirror 142 is eliminated, and as a result, the uniformity of distance measurement accuracy with respect to the direction of the object is improved.

  The height h in the direction parallel to the swing shaft 146 of the light transmitting portion 151a may be equal to or greater than the height H of the light receiving mirror 142 (see FIG. 6).

  According to this configuration, the reflected light 161 reflected over the entire height of the light receiving mirror 142 reaches the light receiving element 160 through the light transmitting portion 151a, so that the height of the light receiving mirror 142 is not wasted. Further, since the height H of the light receiving mirror 142 viewed from the light receiving element 160 is constant regardless of the inclination of the light receiving mirror 142, the amount of received light can be obtained without limiting the height of the reflected light 161 reflected by the light receiving mirror 142. The effect of suppressing the fluctuation is not impaired.

  Although not shown in FIGS. 7 and 8, the light receiving optical unit 150 may further include a band-pass filter that passes light in the band of the measurement light 121.

(Embodiment 2)
Next, the light receiving optical unit 150 according to Embodiment 2 will be described.

  FIG. 9 is a conceptual diagram illustrating an example of a configuration of a light receiving optical unit 150 b as an example of the light receiving optical unit 150. The light receiving optical unit 150b is different from the light receiving optical unit 150a of the first embodiment in that the light shielding member 151 is omitted and the condenser lens 153 is changed.

  FIG. 10 is a perspective view illustrating an example of the appearance of the condenser lens 153. The condensing lens 153 may be made of resin or glass.

  As shown in FIGS. 9 and 10, the dimension of the light transmitting portion 151 a of the condenser lens 153 in the direction perpendicular to the swing shaft 146 is the limit width w. The limit width w only needs to be smaller than the maximum value Wmax of the opening width of the light receiving mirror 142, and the specific size is not limited. For example, the limit width w may be equal to the minimum value Wmin of the opening width of the light receiving mirror 142.

  According to this configuration, the variation in the amount of the reflected light 161 received by the light receiving element 160 is limited to the variation between the amount of received light corresponding to the minimum value Wmin of the aperture width and the amount of received light corresponding to the limit width w. Therefore, the uniformity of ranging accuracy with respect to the direction of the object is improved.

  In particular, when the limit width w is equal to the minimum value Wmin of the aperture width, the amount of light reflected by the light receiving element 160 is the amount of light received corresponding to the minimum value Wmin of the aperture width over the entire measurement range. Thereby, the variation in the amount of received light according to the inclination of the light receiving mirror 142 is eliminated, and as a result, the uniformity of distance measurement accuracy with respect to the direction of the object is improved.

  Note that the height h of the condenser lens 153 in the direction parallel to the swing axis 146 may be equal to or greater than the height H of the light receiving mirror 142 (see FIG. 6).

  According to this configuration, the reflected light 161 reflected over the entire height of the light receiving mirror 142 reaches the light receiving element 160 through the condenser lens 153, so that the height of the light receiving mirror 142 is not wasted. Further, since the height H of the light receiving mirror 142 viewed from the light receiving element 160 is constant regardless of the inclination of the light receiving mirror 142, the amount of received light can be obtained without limiting the height of the reflected light 161 reflected by the light receiving mirror 142. The effect of suppressing the fluctuation is not impaired.

  In order to satisfy the above-described width and height, the condensing lens 153 has a right and left side in a direction orthogonal to the rocking shaft 146 and a direction parallel to the rocking shaft 146 in order to satisfy the above-described width and height. The upper and lower sides may be cut off. However, it is not essential that the condenser lens 153 has a shape in which the left and right sides and the upper and lower sides are cut off. For example, the condensing lens 153 may have a shape in which only the left and right sides are cut off.

  Although not shown in FIGS. 9 and 10, the light receiving optical unit 150 may further include a band-pass filter that passes light in the band of the measurement light 121.

(Embodiment 3)
In the first and second embodiments, in the light receiving optical unit 150, the reflected light 161 reflected by the light receiving mirror 142 and traveling toward the light receiving element 160 passes through a region having a predetermined limit width in a direction orthogonal to the swing axis 146. The configuration in which the reflected light reaches the light receiving element 160 has been described. According to this configuration, an effect of improving the uniformity of distance measurement accuracy with respect to the direction of the object can be obtained.

  In the third embodiment, in addition to the above-described effects, the arrangement of the light receiving optical unit that is advantageous for reducing the size of the measuring apparatus 100 will be described.

  FIG. 11 is a conceptual diagram illustrating an example of the arrangement of the light receiving optical units according to the comparative example. In the comparative example of FIG. 11, assuming a general case where the reflected light 161 is not limited by the limiting width, a luminous flux having a size equal to the maximum value Wmax of the opening width of the light receiving mirror 142 is selected from the luminous flux of the reflected light 161. The light is condensed on the light receiving element 160 by the condenser lens 154.

  In this case, in order to secure an optical path having a width equal to the maximum value Wmax of the aperture width for the reflected light 161, it is necessary to dispose a light receiving optical unit including the condenser lens 154 outside the optical path.

  For example, in the example of FIG. 11, since the end portion P of the condenser lens 154 enters the optical path, the condenser lens 154 cannot be brought closer to the light receiving mirror 142. That is, there is a restriction on downsizing due to the close arrangement of the condenser lens 154 and the light receiving mirror 142.

  This restriction is relaxed in the configuration in which the reflected light 161 is limited by the limit width w.

  FIG. 12 is a conceptual diagram showing an example of the arrangement of the light receiving optical unit 150a.

  FIG. 13 is a conceptual diagram showing an example of the arrangement of the light receiving optical unit 150b.

  As shown in FIGS. 12 and 13, in the configuration in which the reflected light 161 is limited by the limit width w, the limit width w in the direction orthogonal to the oscillation axis of the light flux of the reflected light 161 incident on the light receiving mirror 142. The light beam 161 d that passes outside the region having the light does not reach the light receiving element 160. Therefore, the light receiving optical units 150a and 150b are arranged on the optical path through which the light beam 161d shown with halftone dots in FIGS.

  That is, the light receiving optical units 150a and 150b are intentionally placed on an optical path located outside the region having the limit width w in the direction orthogonal to the swing axis in the optical path of the reflected light 161 incident on the light receiving mirror 142. To place.

  According to this configuration, the light receiving optical units 150 a and 150 b can be arranged close to the light receiving mirror 142 until the end P is in contact with the optical path of the limit width w in the optical path of the reflected light 161. As a result, the degree of freedom of arrangement of the light receiving optical units 150a and 150b is improved, which is useful for reducing the size of the measuring apparatus 100 and improving the design.

  In particular, in the configuration using the condensing lens 153 having the width w of the limit shown in FIG. 10, the reflected light 161 can be limited and condensed only by the condensing lens 153, so that the measuring apparatus 100 by reducing the number of components is used. Useful for downsizing and cost reduction.

  Further, for example, the condenser lens 153 shown in FIG. 10 may be held by the upper and lower sides. By holding the condenser lens 153 on the upper and lower sides and not providing other members on the left and right sides of the condenser lens 153, the condenser lens 153 enters the optical path with the end portion P shown in FIG. The light receiving mirror 142 can be brought closest to the position immediately before.

  This configuration is useful for further miniaturization of the measuring apparatus 100.

  Although the measurement apparatus according to the embodiments of the present invention has been described above, the present invention is not limited to the individual embodiments. Unless it deviates from the gist of the present invention, the embodiment in which various modifications conceived by those skilled in the art have been made in the present embodiment, or a form constructed by combining components in different embodiments is also possible. It may be included within the scope of the embodiments.

  The present invention can be used for a measuring apparatus.

DESCRIPTION OF SYMBOLS 100 Measuring apparatus 110 Case 111 Light transmission window 112 Light reception window 113 Light transmission area 114 Light reception area 119 Light shielding plate 120 Light source 121 Measurement light 130 Light transmission optical part 131 Collimating lens 132 Light shielding member 140 Mirror part 141 Light transmission mirror 142 Light reception mirror 143 Light shielding plate 142a, 142b Projection shape of light receiving mirror 146 Oscillating shaft 150, 150a, 150b Light receiving optical part 151 Light shielding member 151a Light transmitting part 152, 153, 154 Condensing lens 160 Light receiving element 161 Reflected light 161a, 161b, 161c, 161d Light flux 170 Light source drive unit 180 Mirror drive unit 190 Control unit 901, 902 Object

Claims (7)

A mirror having a predetermined mirror width in a direction perpendicular to the swing axis, with the angle formed between the light emitted from the light source and the reflected measurement light of the light emitted from the minimum angle to the maximum angle. And
A light receiving element that receives the reflected light of the measurement object of the reflected measurement light via the mirror unit;
A light receiving optical part on a light receiving optical axis connecting the mirror part and the light receiving element;
The measuring device having a received light amount limiting unit that limits a transmitted light amount with a limited width smaller than a projection size of the mirror width in the light receiving optical axis direction when the angle is the minimum angle. The light receiving amount limiting portion is a light shielding member having a light transmitting portion having the limiting width in a direction perpendicular to the swing axis.
The measuring apparatus according to claim 1. The translucent part has a height equal to or higher than the mirror part in the direction of the swing axis.
The measuring apparatus according to claim 2. The received light amount limiting unit is a lens having the limiting width in a direction perpendicular to the swing axis.
The measuring apparatus according to claim 1. The lens has a height equal to or higher than the mirror part in the direction of the swing axis;
The measuring apparatus according to claim 4. The lens condenses the reflected light reflected by the mirror unit on the light receiving element,
The measuring apparatus according to claim 4 or 5. The light receiving optical unit is disposed outside a region having the limit width in a direction orthogonal to the swing axis in an optical path of the reflected light incident on the mirror unit.
The measuring apparatus according to any one of claims 1 to 6.

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