JPH04337201A - Movable type illumination apparatus - Google Patents

Abstract

PURPOSE:To make the moving speed of a light spot constant. CONSTITUTION:A lighting fixture 1 is rotatively driven around the rotary axis AX1 as the center parallel with an illuminated face in the plane perpendicular to a linear scanning line L set on the illuminated face 2. The angular velocity at which the lighting fixture 1 is rotated is set in proportion to the square of the cosine of the angle psi formed by the straight line connecting the lighting fixture 1 and a light spot against the vertical line drawn from the lighting fixture 1 (point P) to the scanning line L.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable lighting device which scans a light spot formed on a surface to be illuminated in a straight line.

0002

BACKGROUND OF THE INVENTION In recent years, movable lighting fixtures with a moving light spot have come into widespread use in store lighting and the like for the purpose of enhancing the effect of displaying products on display. Currently, in this type of movable lighting equipment, the lighting device is driven to rotate around a predetermined rotation axis at a constant angular velocity.

0003

[Problems to be Solved by the Invention] In the movable lighting fixture having the above configuration, since the angular velocity at which the lighting fixture is rotated is constant,
Assuming that the irradiated surface is flat and the rotational axis of the lamp is parallel to the irradiated surface, the moving speed of the light spot formed on the irradiated surface is determined by the speed at which the light beam from the lamp reaches the irradiated surface. The speed is slowest at a position perpendicular to , and gradually becomes faster as you move away from that position. That is, since the moving speed of the light spot changes from place to place and does not move at a constant speed, there is a problem that the time for illuminating the displayed products becomes uneven.

The present invention aims to solve the above-mentioned problems, and aims to provide a movable lighting fixture that equalizes the time for illuminating displayed products by keeping the moving speed of the light spot constant. It is.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a lighting device that projects a light spot onto a flat surface to be illuminated, and a light spot that projects a light spot on a straight scanning line set on the surface to be illuminated. A drive means for rotating the lamp around a rotation axis provided in a plane perpendicular to the scanning line so that the lamp is scanned, and a driving means for rotating the lamp around a rotation axis provided in a plane perpendicular to the rotation axis so that the lamp is scanned, and and rotation control means for controlling the driving means so that the lamp rotates about the rotation axis at an angular velocity proportional to the square of the cosine of the angle formed by the straight line connecting the rotation axis and the light spot with respect to the perpendicular line. It is.

[0006]

[Operation] According to the above configuration, the driving means rotates the lamp around the rotation axis in a plane perpendicular to the scanning line, so that the light spot is scanned on a straight scanning line set on the irradiated surface. If it is easy to do so, and the straight line connecting the lamp and the light spot is perpendicular to the rotation axis, the light spot can be moved on a straight scanning line set on the illuminated surface by rotating around the rotation axis. In addition, if the straight line connecting the lamp and the light spot is inclined with respect to the rotation axis, simple control such as adjusting the inclination angle with respect to the rotation axis according to the rotational position of the rotation axis can be performed. This makes it possible to move the light spot along a straight scanning line set on the irradiated surface.

Here, in a plane that includes the scanning line and is orthogonal to the rotation axis, it is proportional to the square of the cosine of the angle formed by the straight line connecting the rotation axis and the light spot with respect to the perpendicular line drawn from the rotation axis to the scanning line. The rotation control means controls the drive means so that the lamp rotates around the rotation axis at an angular velocity, so that the moving speed of the light spot on the scanning line is constant, and the light spot is aligned with each displayed product. This makes it possible to equalize the irradiation time.

[0008]

[Example] (Example 1) As shown in FIG. 1(a), the lamp 1 used in this example includes a cylindrical appliance main body 11,
Inside the instrument body 11, a light source (not shown), a reflecting mirror,
Optical elements (not shown) for forming the light beam, such as lenses, are provided. The lamp 1 is rotatably held between both legs of a substantially U-shaped lamp holder 12, and the two legs are connected by a driving means (not shown) such as a motor built into the lamp holder 12. A first axis of rotation A parallel to the central piece
It is driven to rotate around X1. Here, the irradiated surface 2 (
(see FIG. 1(b)) is a plane perpendicular to the center line of the leg piece. Therefore, if the lamp 1 is rotated back and forth around the rotation axis AX1, the light spot projected onto the irradiated surface 2 will move back and forth on the scanning line L, which is a straight line. In short, the rotation axis AX1 is set to be parallel to the irradiated surface 2 in a plane perpendicular to the scanning line L.

Under these conditions, the moving speed of the light spot formed on the irradiated surface 2 can be determined as follows. That is, as shown in FIG. 1(b), the length of the perpendicular drawn from the lamp 1 (represented by point P) to the irradiated surface 2 (i.e., the distance between the lamp 1 and the irradiated surface 2)
is D, and the angle made by the straight line connecting the lamp 1 and the light spot with this perpendicular is ψ (-90°<ψ<90°), and the angle of the irradiated surface 2 when the angle ψ changes by a small angle δψ is If the moving distance of the light spot above is δX, then the following equation holds true.

[0010] δX=D・tan (ψ+δψ)−D・t
If we perform Taylor expansion of an ψtan (ψ+δψ), we get
tan (ψ+δψ)=tan ψ+δψ
・(1/cos2ψ)+... ∴δX≒(D/
cos2ψ)・δψ
(1) If both sides of equation (1) are divided by the minute time δt and δt→0, then V=(D/cos2ψ)・ω ∴ω
=(V/D)・cos2ψ
(2) However, V is the moving speed of the light spot on the irradiated surface (=dx/dt),
ω is the angular velocity (=d
ψ/dt). In short, if we want to keep the moving speed of the light spot constant on the scanning line L set on the irradiated surface 2, we can rotate the lamp 1 at an angular velocity ω proportional to the square of the cosine of the angle ψ. be. Further, the proportionality constant can be given by the moving speed V of the light spot and the distance D between the lamp 1 and the illuminated surface 2.

In order to control the angular velocity ω according to the rotation angle ψ of the lamp 1, as shown in FIG. The angular velocity may be set by the control section 4, and the drive section 5, which is the drive means, may be feedback-controlled based on the set angular velocity. Further, the moving speed V, which determines the proportionality constant, and the distance D between the lamp 1 and the irradiated surface 2 are inputted from an input instruction unit 6, which includes a keyboard or the like. Additionally, the maximum value of the angle ψ is also input in order to specify the scanning range of the light spot. As the rotation angle detection section 3, a potentiometer or the like may be used when it is desired to obtain an analog output according to the rotation angle of the lamp 1, and a rotary encoder or the like may be used when it is desired to obtain a digital output according to the rotation angle of the lamp 1. . The rotation angle of the lamp 1 detected by the rotation angle detection section 3 is input to the control section 4 together with the proportionality constant input from the input instruction section 6, and the angular velocity is determined by calculating equation (2). By controlling the drive unit 5 so that the lamp 1 rotates at the angular velocity determined in this manner, the light spot can be scanned at a constant speed.

Note that in order to set the proportionality constant in equation (2), the moving speed V of the light spot, the lamp 1 and the irradiated surface 2 are
The distance D from・co
s2ψ
(3) may be modified to adjust only one proportionality constant α while checking the movement of the light spot. If this method is adopted, the input instruction section 6 for inputting the proportionality constant α
This can be realized with a simple configuration such as a variable resistor. Further, if the drive unit 5 is configured by combining a motor and a cam, etc., it is possible to configure the drive unit 5 so that the relationship shown in equation (2) is established between the rotation angle and the angular velocity. If such a drive section 5 is adopted, the rotation angle detection section 3 becomes unnecessary, and open control that only sets a proportionality constant becomes possible.

(Embodiment 2) In this embodiment, as shown in FIG. 1(a), a second rotation axis AX2 is provided which is orthogonal to the center piece in a plane including both leg pieces of the lamp holder 12, and this rotation The lamp holder 12 is also rotated around the axis AX2. Further, it is assumed that the irradiated surface 2 is parallel to the rotation axis AX2.

Here, if the direction of light emitted from the lamp 1 is perpendicular to the plane including both leg pieces, the lamp 1 can be rotated around the second rotation axis AX2 instead of the first rotation axis AX1. This embodiment is substantially the same as the first embodiment, with the only difference being that it is rotated. However, the light fixture 1 is placed on a ceiling or the like, and the axis direction of the rotation axis AX2 is normally set in the vertical direction, and the irradiated surface 2 is assumed to be a wall surface, so the light projected from the light fixture 1 is The direction is generally inclined with respect to the plane containing both leg pieces. In this case, the rotation axis AX2
When the lamp 1 is rotated around the irradiation target surface 2, the light spot is scanned in an arc shape. therefore,
Normally, it is not possible to scan on a straight scanning line. Therefore, in order to scan the light spot in a straight line, it is necessary to satisfy the following conditions. That is, as shown in FIG. 3, the distance between the lamp 1 (represented by point P) and a plane including the scanning line L and perpendicular to the irradiated surface 2 is H,
The angle that the straight line connecting the lamp 1 and the light spot makes with the rotation axis AX2 (i.e., the rotation angle of the rotation axis AX1)
is θ, the distance between the rotation axis AX2 and the irradiated surface 2 in the above plane is D, and the rotation angle of the rotation axis AX2 in the above plane is ψ. In order for the scanning line L to become a straight line, the following ( 4)
It is sufficient if the formula holds true.

D=H・tan θ・cos ψ
∴tan θ=(D/H)/cos ψ
(4) Now, if the angle θ when the light spot is located on the leg of the perpendicular line drawn from the rotation axis AX2 to the irradiated surface 2 in the above plane is θ0, then D=H・tan θ0

Since (5), by equations (4) and (5),
tan θ=tan θ0 /cos ψ
(
6) holds true. In short, so that equation (6) holds true, the rotation angle ψ of the rotation axis AX2 is
By controlling the rotation angle θ, the scanning lines can be set on a straight line. On the other hand, if the condition of equation (6) is satisfied, it is guaranteed that the scanning line is a straight line, so the angular velocity ω when rotating the lamp 1 around the rotation axis AX2 is the same as in Example 1. The same, ω=(V/D)・cos2ψ
(2)
Or, ω=α・cos2ψ

The angular velocity ω may be controlled so that (3) holds true. The parameters input from the input instruction unit 6 are the moving speed V of the light spot, the positional relationship between the lamp 1 and the irradiated surface 2 (dimension H
, D), equations (2) and (4) may be used, and the parameters to be input are the reference angle θ of the rotation axis AX1.
0 and the proportionality constant α, control may be performed using equations (3) and (6). It goes without saying that here as well, the maximum value of the angle ψ is input in order to specify the scanning range. The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted.

(Embodiment 3) In this embodiment, as in Embodiment 2, the mounting surface of the luminaire 1 and the irradiated surface 2 intersect, as in the case where the luminaire 1 is formed on the ceiling and the light spot is formed on the wall surface. This assumes that you are. In addition, the lamp holder 12 is shown in FIG.
As shown in a), it is assumed that it can rotate around a third rotation axis AX3 that is orthogonal to the rotation axis AX2.

In this case, the rotation axis AX2 is rotated so that the plane including both leg pieces is perpendicular to the irradiated surface 2, and the plane including the straight line connecting the lamp 1 and the light spot and the scanning line L is rotated. The rotation axis AX3 is rotated so that the rotation axis AX2 is perpendicular to the rotation axis AX2. With this setting, by rotating the lamp 1 around the rotation axis AX1,
The light spot can be scanned over a straight scanning line L. Therefore, as shown in FIG. 4(b), the distance between the horizontal plane including the scanning line L and the lamp 1 is set to H, and the distance between the horizontal plane and the lamp 1 is
If the distance from the intersection with the vertical line drawn from
E=(H2 +D2)1/2
(7)
Therefore, when the moving speed of the light spot is V, the angular velocity ω at which the lamp 1 is rotated around the rotation axis AX1 is:
ω=(V/E)・cos2ψ
(8)
can be set. Here, the angle ψ is the rotation axis AX
Needless to say, the maximum value of the angle ψ, which is the rotation angle around 1, is input in order to limit the scanning range. In short, the parameters to be input are distances H, D,
The moving speed V and angle ψ of the light spot reach their maximum values. Also, if D/H=tan θ0, the rotation angle of the rotation axis AX3 can be specified by the angle θ0, and E=H/cos
Since θ0 = D/cos θ0, one of the distances H and D and the maximum value of the angle θ0 and the angle ψ can be used as input parameters. Furthermore, if the angle θ0 can be determined, the operation will be the same as in Example 1, so V/E=β
Then, formula (8) is written as ω=β・cos2
ψ
(9) may be modified to adjust the proportionality constant β. In this case, there is no need to actually measure the distances H and D, and the proportionality constant β can be adjusted while observing the moving speed of the light spot on site. The other configurations and operations are the same as those in the first embodiment, so their explanations will be omitted.

[0018]

Effects of the Invention As described above, the driving means of the present invention rotates the lamp around the rotation axis in a plane orthogonal to the scanning line, so that the light spot can be scanned in a straight line on the irradiated surface. If it is easy to scan on a line, and the straight line connecting the lamp and the light spot is orthogonal to the rotation axis, then by rotating around the rotation axis, the light spot can be scanned on a straight line set on the irradiated surface. In addition, if the straight line connecting the lamp and the light spot is inclined to the rotation axis, it is easy to adjust the inclination angle to the rotation axis according to the rotational position of the rotation axis. This has the advantage that the light spot can be moved along a straight scanning line set on the irradiated surface simply by performing appropriate control.

Here, in a plane that includes the scanning line and is orthogonal to the rotation axis, it is proportional to the square of the cosine of the angle formed by the straight line connecting the rotation axis and the light spot with respect to the perpendicular line drawn from the rotation axis to the scanning line. The rotation control means controls the drive means so that the lamp rotates around the rotation axis at an angular velocity, so that the moving speed of the light spot on the scanning line is constant, and the light spot is aligned with each displayed product. This has the effect of making it possible to equalize the irradiation time.

[Brief explanation of the drawing]

FIG. 1 shows Example 1, (a) is a perspective view of a lamp, (b
) is an operation explanatory diagram.

FIG. 2 is a block diagram common to each embodiment.

FIG. 3 is an explanatory diagram of the operation of the second embodiment.

FIG. 4 shows Example 3, (a) is a perspective view of the lamp, (b
) is an operation explanatory diagram.

[Explanation of symbols]

1. Lighting equipment 2 Irradiated surface 3 Rotation angle detection section 4 Control section 5 Drive part 6 Input instruction section

Claims (1)

[Claims] [Claim 1] A lamp for projecting a light spot onto a flat surface to be illuminated, and a lamp provided in a plane perpendicular to the scanning line so that the light spot is scanned along a straight scanning line set on the surface to be illuminated. The angle formed by the driving means that rotates the lamp around the rotation axis and the straight line connecting the rotation axis and the light spot with respect to the perpendicular drawn from the rotation axis to the scanning line in a plane that includes the scanning line and is perpendicular to the rotation axis. 1. A movable lighting fixture comprising: rotation control means for controlling a driving means so that the lighting fixture rotates around a rotation axis at an angular velocity proportional to the square of the cosine of .