JPH0875466A - Automatic inclination correcting device for laser projecting device - Google Patents

Abstract

PURPOSE: To provide an automatic inclination correcting device for laser projecting device which has a wide correcting range and a high correcting precision. CONSTITUTION: This device is formed out of a first collimator lens 2 for making the laser beam L emitted from a laser diode 1 upward into a parallel light, a transparent vessel 3 transmitting the parallel light from a projecting lens 2, a projecting lens 4 for converging the light transmitted by the transparent vessel 3 to form the secondary light source 11 of the laser diode 1 in the position of a focal length f2, and a second collimator lens 5 for making the light from the secondary light source 11 into a parallel light. Silicone oil C is sealed in the transparent vessel 3, and a space 7 in contact with the surface of the silicone oil C is formed in the upper part of the transparent vessel 3. The focal lengths f2, f3 with the projecting lens 4 and the second collimator lens 5 are set according to the refractive index of the silicone oil C, respectively, so that the parallel light from the second collimator lens is emitted vertically upward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tilt correction device for a laser projection device, and more particularly to an automatic tilt correction device suitable as a tilt correction device for a laser projection surveying instrument used in construction work.

[0002]

2. Description of the Related Art As a conventional automatic inclination correction device for a laser projection surveying instrument, one shown in FIGS. 7 and 8 is known (JP-A-63-222214).

FIG. 7 is a vertical cross-sectional view of a laser projection surveying instrument equipped with a conventional automatic tilt correction device, and FIG. 8 is a vertical cross-sectional view showing a state in which the laser projection surveying device of FIG. 7 is tilted.

The surveying instrument main body 409 of this laser projection surveying instrument
A leveling device 408 is provided in the lower part of the. A laser diode 401 is provided above the surveying instrument main body 409 so that the laser light L can be emitted downward, and an automatic tilt correction device is provided below the laser diode 401.

The automatic tilt correction device is provided with a laser diode 4
A projection lens 402 that collimates the laser light L emitted downward from 01 to parallel light and a transparent container 403 through which the parallel light from the projection lens 402 is transmitted are provided. Transparent container 40
3 is divided into two upper and lower chambers, silicone oils C1 and C2 are enclosed in the respective chambers, and spaces 408a and 408b in contact with the liquid surfaces of the silicone oils C1 and C2 are formed in the upper portion of each chamber. There is. Transparent container 4
03 upper plane part 403a, middle plane part 403b, and lower plane part 403c are parallel to each other.

As shown in FIG. 8, when the surveying instrument main body 409 is tilted by an angle θ1, the silicone oils C1 and C2 in the transparent container 403 are wedge-shaped with a gradient angle θ1. The laser light L emitted from the laser diode 401 and collimated by the light projecting lens 402 is wedge-shaped silicone oil C.
When it passes through C1 and C2, it is refracted and becomes a laser beam L having a deviation angle θ2, which is emitted to the outside of the surveying instrument body 409.

Assuming that the refractive indices of the silicone oils C1 and C2 are n1 and n2, respectively, the correction conditional expression θ2 = (n
1 + n2-2) θ1 is given, and if the silicone oils C1 and C2 of n1 = n2 = 1.5 are used, the laser beam L
The inclination correction of will be established. That is, the laser light L is automatically corrected so as to be directed in the vertical direction, and the measurement error due to the inclination of the surveying instrument main body 409 is corrected.

[0008]

However, there is no silicone oil having an appropriate viscosity and a refractive index of exactly 1.500, and in reality, the refractive index is 1.49 or 1.
Since there is no choice but to use the one of No. 51, there is a problem that the correction accuracy is deteriorated due to the above-mentioned correction conditional expression.

On the other hand, if the automatic inclination correction device is used within a range in which the correction accuracy does not deteriorate, the correction range by the automatic inclination correction device becomes considerably narrow, for example, about ± 10 minutes, and as a result, the bubble tube It is necessary to perform the leveling work by rotating the leveling screw 408a while looking at it, and there is a problem that setting of the laser projection surveying instrument becomes troublesome.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an automatic tilt correction device for a laser projection device having a wide correction range and high correction accuracy.

[0011]

In order to solve the above-mentioned problems, an automatic tilt correction device for a laser projection device according to a first aspect of the present invention is a first device for converting light emitted upward from a light source into parallel light. In an automatic tilt correction device of a laser projecting device comprising an optical member, a container through which light from the light source is transmitted, and a transparent liquid having a free liquid surface contained in the container, the liquid is transmitted. A secondary light source optical member that collects the generated light to form a secondary light source of the light source; and a second optical member that converts the light from the secondary light source into parallel light. The focal lengths of the secondary light source optical member and the second optical member were set in accordance with the refractive index of the liquid so that the parallel light of (1) was emitted in the vertical direction.

According to the second aspect of the present invention, there is provided an automatic tilt correcting device for a laser projecting device, comprising: a first optical member for converting light emitted downward from a light source into first parallel light; In an automatic tilt correction device for a laser projecting device, which comprises a container through which light is transmitted and a transparent liquid which is contained in the container and has a free liquid surface, the light transmitted through the liquid is condensed and A secondary light source optical member for forming a secondary light source of the light source, a second optical member for converting light from the secondary light source into second parallel light, and the second parallel light from the second optical member. And a second optical member for reflecting the second parallel light from the second optical member in the vertical direction. The focal length with respect to the optical member was set according to the refractive index of the liquid.

Further, in the automatic tilt correcting device of the laser projecting device according to the third aspect of the present invention, the first optical member for converting the light emitted downward from the light source into the first parallel light, and the light source from the light source. In an automatic tilt correction device for a laser projecting device, which comprises a container through which light is transmitted and a transparent liquid which is contained in the container and has a free liquid surface, the light transmitted through the liquid is condensed and A secondary light source optical member for forming a secondary light source of the light source, a second optical member for converting light from the secondary light source into second parallel light, and the second parallel light from the second optical member. And a third optical member for reflecting the second parallel light, and the second parallel light is emitted in the same inclination direction as the first parallel light with respect to the vertical axis at an inclination angle twice that of the first parallel light. like,
The focal lengths of the secondary light source optical member and the second optical member are respectively set according to the refractive index of the liquid, and the second parallel light is horizontally reflected by the reflection of the third optical member. The reflecting surface of the third optical member was set in a predetermined direction so as to be emitted.

According to a fourth aspect of the present invention, there is provided an automatic tilt correction device for a laser projecting device, wherein the refractive index of the liquid is n, the focal length of the secondary light source optical member is f2, and the second optical member has a focal length of f2. F3 / f2, where f3 is the focal length and θ is the tilt angle of the parallel light from the first optical member with respect to the vertical axis.
= Tan {Sin ^-1 (nSinθ) -θ} / Tan
The relationship of θ is almost satisfied.

Further, in the automatic tilt correction device for a laser projecting device according to a fifth aspect of the present invention, the light incident end of the container is formed of the first optical member and faces the light incident end. The light emitting end of the container is formed by the secondary light source optical member.

[0016]

In the automatic tilt correction device for the laser projection device according to the first aspect of the present invention, the secondary light source optical member for converging light that has passed through the liquid in the container from below to above to form a secondary light source of the light source. And a second optical member for collimating the light from the secondary light source into parallel light, and the secondary light source optical member and the second optical member so that the parallel light from the second optical member is emitted upward in the vertical direction. Since the focal length with respect to the optical member is set according to the refractive index of the liquid in the container, a wide tilt correction range and high tilt correction accuracy can be obtained.

Further, in the automatic tilt correcting device of the laser projecting device according to the second aspect of the present invention, a tilt correcting range and high tilt correcting accuracy can be obtained.

Further, in the automatic tilt correction device for the laser projecting device according to the third aspect of the present invention, the secondary light source for converging the light transmitted through the liquid in the container from above to below to form the secondary light source of the light source. An optical member, a second optical member for converting light from the secondary light source into second parallel light, and a third optical member for reflecting the second parallel light from the second optical member, Focus of the secondary light source optical member and the second optical member so that the second parallel light is emitted in the same inclination direction as the first parallel light with respect to the vertical axis at an inclination angle of twice the first parallel light. The distance is set according to the refractive index of the liquid, and the reflecting surface of the third optical member is moved in a predetermined direction so that the second parallel light is emitted in the horizontal direction by the reflection of the third optical member. The laser level device has a wide tilt correction range and high tilt correction accuracy because it is set toward It can be.

Further, in the automatic tilt correction device for a laser projecting device according to a fourth aspect of the present invention, the parallel light from the second optical member is emitted in the vertical direction, or the second parallel light is the first light with respect to the vertical axis. 2 of the first parallel light in the same inclination direction as the first parallel light
Since the light is emitted with a double tilt angle, a wide tilt correction range and high tilt correction accuracy can be obtained.

Further, in the automatic tilt correction device for the laser projector of the fifth aspect of the invention, the light incident end of the container is formed of the first optical member, and the light is emitted from the container facing the light incident end. Since the end portion is formed of the secondary light source optical member, the structure can be simplified.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram showing an automatic tilt correction device for a laser projection device according to a first embodiment of the present invention.

The automatic tilt correction device includes a first collimator lens (first optical member) 2 for collimating a laser beam L1 emitted upward from a laser diode (light source) 1 into parallel light.
, A transparent container (container) 3 through which the parallel light from the first collimator lens 2 is transmitted, and the light transmitted through the transparent container 3 is condensed to the laser diode 1 at the position of the focal length f2.
With a projection lens (secondary light source optical member) 4 for forming a secondary light source 11 such as a convex lens or a concave lens, and a second collimator lens (second optical member) 5 for collimating light from the secondary light source 11 into parallel light. It is configured. The first collimator lens 2 and the like constituting this automatic tilt correction device are fixed in the device main body of a laser projecting device such as a laser level device.

The laser diode 1 is arranged at the position of the focal length f1 of the first collimator lens 2.

Silicone oil C having a refractive index of 1.51 is enclosed in the transparent container 3, and a space 7 in contact with the liquid surface of the silicone oil C is formed in the upper part of the transparent container 3. The silicone oil C does not necessarily have to be sealed in the transparent container 3. The upper surface 3a and the lower surface 3b of the transparent container 3 are parallel to each other.

The position of the focal length f3 of the second collimator lens 5 and the position of the secondary light source 11 are matched.

Next, the operation principle of this automatic inclination correction device will be described.

The laser light L from the laser diode 1 is collimated by the first collimator lens 2 and is incident on the silicone oil C in the transparent container 3. When the device main body of the laser projecting device is tilted by an angle θ1, the transparent container 3 is also tilted, but the liquid level of the silicone oil C in the transparent container 3 is kept horizontal, so that it becomes a wedge shape having a gradient angle θ1. The laser beam L transmitted through the silicone oil C is incident on the projection lens 4 with an angle θ2, θ2 = Sin ⁻¹ (n · Sin θ1) −θ1 (1). (N is the refractive index of the silicone oil C) The laser light L transmitted through the silicone oil C is condensed by the projection lens 4, and the secondary light source 11 of the laser diode 1 is formed at the position of the focal length f2 of the projection lens 4. .

The secondary light source 11 is formed at a position separated from the vertical axis in the horizontal direction by a distance d d = f2 · Tan θ2 (2).

The laser light L from the projection lens 4 enters the second collimator lens 5, becomes parallel light having the angle θ3 θ3 = Tan ⁻¹ (d / f3) (3) and is emitted in the vertical direction. To be done.

Substituting the expressions (1) and (2) into the expression (3), θ3 = Tan ⁻¹ × {f2 · Tan [Sin ⁻¹ (n · Sin θ1) −θ1] / f3} (4) Expression And the correction angle is obtained.

By setting θ1 = θ3 = θ from the equation (4) and deriving the correction condition equation, f3 / f2 = Tan [Sin ⁻¹ (n · Sinθ) −θ] / Tanθ (5) Arbitrary correction angle), the silicone oil C
If the refractive index of is determined, the focal lengths f2 and f3 of the projection lens 4 and the second collimator lens 5 can be set.

Since the automatic inclination correction device shown in FIG. 2 is configured to satisfy the expression (4), the laser light L is always emitted vertically.

For example, θ = 1 °, n = 1.51, f2 =
If it is set to 20 mm, f3 = 10.2 m from the formula (5).
m is required. From this, from the equation (4), the correction angle θ3
Is obtained, θ1 = 10 ′, θ3 = 10 ′ 0 ″, θ1 =
Θ3 = 30 ′ 0.05 ″ at 30 ′, θ3 = at θ1 = 1 °
Correctly corrected to 1 ° 0'0.4 '' etc.

As one application example of this automatic inclination correction device, a laser vertical device for emitting a laser beam L vertically upward can be considered.

According to the automatic tilt correcting apparatus of the first embodiment, since the tilt correcting range is wide, a leveling device for leveling the apparatus body is not required, the working efficiency is improved, and the high tilt correcting accuracy is obtained. Can be obtained. Further, it is possible to use a liquid having an optimum viscosity regardless of the refractive index, which increases the degree of freedom in liquid selection.

FIG. 2 is a vertical cross-sectional view showing an application example in which the automatic tilt correction device of FIG. 1 is applied to a laser level device. FIG.
The same parts as those of the embodiment shown in FIG.

This laser level device includes a base plate 8 and
The main body 9 is attached to the base plate 8. The bottom surface of the base plate 8 is provided with a screw hole 8a for attaching a tripod (not shown). Device body 9
The automatic tilt correction device of FIG. 1 is incorporated therein. That is, the laser diode 1 is fixed to the lower part inside the apparatus main body 9, and the first collimator lens 2, the transparent container 3, the projection lens 4, and the second collimator lens 5 are fixed above the laser diode 1, respectively. Further, the focal length f2 of the projection lens 4 is set so as to satisfy the conditional expression for the correction.
And the focal length f3 of the second collimator lens 5 is set.

A cylindrical rotating body 10 is arranged above the second collimator lens 5, and the rotating body 10 has a bearing 1
It is rotatably attached to the upper part inside the apparatus main body 9 via 5. A penta mirror 1 that reflects the laser light L from the second collimator lens 5 at a right angle in the rotating body 10.
2, 12 are fixed. Rotating body 10 is transmission belt 1
It can be rotated by a motor 14 via 3.

According to the laser level device of this application example,
Even if the entire laser level device is tilted, the laser light L is emitted vertically from the second collimator lens 5, so that the laser light L is reflected by the pentamirrors 12 and 12 to become horizontal light, and further, the pentamirror 12 , 12 are rotated by the motor 14, so that the laser light L reflected by the pentamirrors 12, 12 is emitted to the outside through the window 9a, and is scanned in the horizontal direction by 360 °.

FIG. 3 is a vertical cross-sectional view showing another application example in which the automatic inclination correction device of FIG. 1 is applied to a laser vertical device. The same parts as those of the embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

Like the laser level device of FIG. 2, an automatic tilt correction device is built in the device main body 109, but in this application example, the lower surface portion (light incident end portion) of the transparent container 103.
Is formed by the first collimator lens 102, and the upper surface portion (light emission end portion) of the transparent container 103 is formed by the projection lens 104.

Further, as in the above-described embodiment, the focal length f of the projection lens 104 is set so as to satisfy the correction conditional expression.
2 and the focal length f3 of the second collimator lens 5 are set.

A right-angle prism 16 is arranged above the second collimator lens 5, a parallel prism 17 having a half mirror surface 17a is arranged to the left of the right-angle prism 16, and a parallel prism 17 is to the left of the parallel prism 17. A right angle mirror 18 is arranged.

The laser light La emitted vertically from the second collimator lens 5 is reflected by the rectangular prism 16 to become horizontal light Lb, and the half mirror surface 1 of the parallel prism 17 is reflected.
2a for straight light Lc and right light Ld bent downward at 7a
Be divided. The straight traveling light Lc is emitted vertically upward by the right-angle mirror 18, and visible laser light is projected on the ceiling or the like.
Further, the right-angled light Ld is changed in its optical path to be more right-angled in the parallel prism 17, and is emitted vertically downward by the right-angled mirror 18, so that visible laser light is projected on the floor or the like.

According to this application example, the lower surface of the transparent container 103 is formed by the first collimator lens 102, and the upper surface of the transparent container 103 is formed by the projection lens 104. The number of points is reduced, which contributes to downsizing of the laser vertical device.

FIG. 4 is an overall configuration diagram showing an automatic tilt correction device for a laser projection device according to a second embodiment of the present invention.
The same parts as those of the first embodiment shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Although the tilt correction when the laser light L is emitted upward from the laser diode 1 has been described in the first embodiment, the laser diode 1 is used in this embodiment.
The tilt correction when the laser beam L is emitted downward from the above will be described.

The arrangement of the first collimator lens 2, the transparent container 3, the projection lens 4 and the second collimator lens 5 is opposite to that of the first embodiment shown in FIG. The difference lies in the structure that the Porro prism 19 is arranged below.

The reason why the Porro prism (third optical member) 19 is arranged below the second collimator lens 5 is that the device body to which the laser diode 1 and the like are fixed is inclined.
Laser light L emitted from the second collimator lens 5
Contrary to the case of the first embodiment, since it bends in the same direction as the inclination direction of the apparatus main body, that is, in the direction opposite to the correction direction, at a double angle, the laser beam L is reflected and reflected to change the correction angle θ4. Get
This is because the laser light L is always emitted vertically downward.

As one application example of this automatic inclination correction device, a laser vertical device for emitting a laser beam L vertically downward can be considered.

According to the automatic inclination correcting apparatus of the second embodiment, the same effect as that of the first embodiment can be obtained.

FIG. 5 is a vertical cross-sectional view showing an application example in which the automatic inclination correction device of FIG. 4 is applied to a laser level device. Figure 2
The same parts as those of the laser level device are designated by the same reference numerals and the description thereof is omitted. In this application example, the laser diode 1
Is fixed to the upper part inside the device main body 209, and below the laser diode 1, the first collimator lens 2, the transparent container 3, the projection lens 4 and the second collimator lens 5 are sequentially fixed, and the laser level device of FIG. The positional relationship is opposite to the case.

A Porro prism 19 is arranged below the second collimator lens 5, and a rotating body 10 having penta mirrors 12 and 12 is arranged below the Porro prism 19.

According to the laser level device of this embodiment,
Even if the laser beam L is emitted from the second collimator lens 5 in a direction opposite to the correction direction when the device body 209 is inclined, the laser beam L is reflected and reflected by the Porro prism 19 and is always vertically downward. Since the laser light L is emitted to the pentamirrors 12, 12, the laser light L is reflected by the pentamirrors 12 and 12 to become horizontal light, and the rotating body 10 holding the pentamirrors 12 and 12 is rotated by the motor 14. The laser light L reflected by 12, 12 is emitted to the outside through the window 209a, and 360
It is scanned in the ° direction.

FIG. 6 is a vertical cross-sectional view showing another application example in which the automatic inclination correction device of FIG. 4 is applied to a laser level device.
The same parts as those of the laser level device shown in FIG. In this application example, the device main body 309
In the lower part of the inside, instead of the Porro prism 19, a conical mirror 20
Is used.

According to the laser level device of this embodiment,
Even if the laser beam L is emitted from the second collimator lens 5 while being inclined in the direction opposite to the correction direction when the device body 309 is inclined, the laser beam is corrected in the horizontal direction by the mirror action of the conical mirror 20, and the laser beam is corrected. L is emitted to the outside through the window 309a, and is scanned in the direction of 360 ° in the horizontal plane.

In the laser vertical apparatus shown in FIG. 3, the case where the lower surface of the transparent container 3 is formed by the first collimator lens 102 and the upper surface is formed by the projection lens 104 has been described. Also in each of the examples except the above, one of the upper surface portion and the lower surface portion of the transparent container 3 may be formed by the first collimator lens 2 and the other may be formed by the projection lens 4.

Further, the number of the transparent containers 3 may be one or plural, and further, the laser beam L may be scanned in the direction of 360 ° in the vertical plane, or in the inclined plane inclined with respect to the horizontal plane. You may make it scan in a 360 degree direction.

[0059]

As described above, the first aspect of the present invention is as follows.
According to the automatic tilt correction device of the laser projector of the invention described above, for example, since the tilt correction device has a wide tilt correction range as a tilt correction device for a laser vertical device that emits laser light vertically upward, leveling for leveling the device body is performed. A device is not required, work efficiency is improved, and high inclination correction accuracy can be obtained.

Further, according to the automatic tilt correcting device of the laser projecting device of the second aspect of the invention, the tilt correcting device of the laser vertical device for emitting the laser beam vertically downward has a wide tilt correcting range and a high tilt correcting. You can get the accuracy.

Further, according to the automatic tilt correcting device of the laser projecting device of the third aspect of the invention, a wide tilt correcting range and high tilt correcting accuracy can be obtained as the tilt correcting device of the laser level device.

Further, according to the automatic tilt correcting device of the laser projecting device of the fourth aspect, a wide tilt correcting range and high tilt correcting accuracy can be obtained as the tilt correcting device.

Further, according to the automatic tilt correcting device of the laser projecting device of the fifth aspect of the present invention, the structure can be simplified, which contributes to downsizing of the laser projecting device.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an automatic tilt correction device of a laser projection device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing an application example in which the automatic tilt correction device of FIG. 1 is applied to a laser level device.

FIG. 3 is a vertical cross-sectional view showing another application example in which the automatic tilt correction device of FIG. 1 is applied to a laser vertical device.

FIG. 4 is an overall configuration diagram showing an automatic tilt correction device for a laser projection device according to a second embodiment of the present invention.

5 is a vertical cross-sectional view showing an application example in which the automatic tilt correction device of FIG. 4 is applied to a laser level device.

6 is a vertical cross-sectional view showing another application example in which the automatic tilt correction device of FIG. 4 is applied to a laser level device.

FIG. 7 is a vertical cross-sectional view of a laser projection surveying instrument equipped with a conventional automatic tilt correction device.

8 is a vertical cross-sectional view showing a state where the laser projection surveying instrument of FIG. 7 is tilted.

[Explanation of symbols]

 1 Laser diode 2,102 1st collimator lens 3 Transparent container 4 104 Projection lens 5 2nd collimator lens 7 Space 10 Rotating body 12 Penta mirror 16 Right angle prism 17 Parallel prism 18 Right angle mirror 19 Porro prism 20 Conical mirror C Silicone Oil f2 focal length of projection lens f3 focal length of second collimator lens

Claims (5)

[Claims] 1. A first optical member that collimates light emitted upward from a light source into parallel light, a container through which light from the light source is transmitted, and a transparent container that is housed in the container and has a free liquid surface. In an automatic tilt correction device of a laser projector including a liquid, a secondary light source optical member that collects light that has passed through the liquid to form a secondary light source of the light source, and light from the secondary light source. A second optical member for converting the secondary light source optical member and the second optical member so that the parallel light from the second optical member is emitted in the vertical direction. An automatic tilt correction device for a laser projecting device, wherein the distance is set according to the refractive index of the liquid. 2. A first optical member for converting light emitted downward from a light source into first parallel light, a container through which light from the light source is transmitted, and a free liquid surface contained in the container. In a device for automatically correcting inclination of a laser projecting device, the secondary light source optical member for condensing light transmitted through the liquid to form a secondary light source of the light source, and the secondary light source. A second optical member that converts light from the second parallel light into second parallel light; and a third optical member that reversely reflects the second parallel light from the second optical member vertically and horizontally, The second light source optical member and the second optical member so that the second parallel light from the second optical member is emitted in the vertical direction.
2. The automatic tilt correction device for a laser projection device, wherein the focal length of the optical member is set according to the refractive index of the liquid. 3. A first optical member for converting light emitted downward from a light source into first parallel light, a container through which light from the light source is transmitted, and a free liquid surface housed in the container. In a device for automatically correcting inclination of a laser projecting device, the secondary light source optical member for condensing light transmitted through the liquid to form a secondary light source of the light source, and the secondary light source. A second optical member that converts the light from the second parallel light into a second parallel light; and a third optical member that reflects the second parallel light from the second optical member, Of the secondary light source optical member and the second optical member such that the light is emitted in the same inclination direction as the first parallel light with respect to the vertical axis at an inclination angle of twice the first parallel light. The distance is set according to the refractive index of the liquid, and the second parallel light is the third light. As is emitted in the horizontal direction by the reflecting member, the automatic deskew system of laser projection device being characterized in that the reflecting surface of the third optical member is set toward a predetermined direction. 4. The refractive index of the liquid is n, the focal length of the secondary light source optical member is f2, the focal length of the second optical member is f3, and the parallel light from the first optical member with respect to the vertical axis. Where θ is the inclination angle of f3 / f2 = Tan {Sin ⁻¹ (n · Sin θ) −
2. The relationship of θ} / Tanθ is substantially satisfied.
2. An automatic tilt correction device for a laser projecting device according to 2 or 3. 5. A light incident end of the container is formed of the first optical member, and a light emitting end of the container facing the light incident end is formed of the secondary light source optical member. The automatic tilt correction device for a laser projection device according to claim 1, 2, 3, or 4.