HK1241645A1 - Illumination device - Google Patents

Abstract

[Problem] To appropriately maintain the distance between the eyes of a user and a target object and to illuminate above a desk, using an appropriate amount of illumination. [Solution] An illumination device comprising: a light source 62 for illuminating above a desk D; an arm mechanism 30 having built therein a motor for moving the position of the light source 62; a face camera 21 that detects the eye position of a user H; desk cameras 63, 64 that detect the illumination distribution above the desk D; an image processing unit 120 that calculates the distance to the eyes of the user H and the desk D and calculates the posture of the user H, on the basis of a face image obtained by the face camera 21 and a desk image obtained by the desk cameras 63, 64; a calculation unit 130 that calculates the optimum light source position for the light source 62 whereby scattering of illumination distribution above the desk is minimized, on the basis of the posture of the user D found by the image processing unit 120 and the illumination distribution obtained by the desk cameras; an alarm unit 140 that generates an alarm if the distance is no more than a prescribed value; and a control unit 110 that operates the arm mechanism 30 such that the light source 62 travels to the optimum light source position.

Description

Lighting device

Technical Field

The present invention relates to an illumination device, and more particularly, to an illumination device capable of appropriately maintaining the posture of a user and appropriately illuminating a table.

Background

A lighting device called a "desk lamp (desk light)" is generally used (see, for example, patent documents 1 to 3). Such an illumination device is adjusted by a user by appropriately changing the position so that a desired position obtains appropriate illuminance.

Such a table lamp can be improved in various ways, and an illumination device in which a motor is provided at a movable portion for changing an illumination direction is known (for example, see patent document 1). Further, there is known an illumination device that adjusts a color or controls an irradiation range when a focus adjustment function of an eye is degraded due to age or fatigue (for example, see patent document 2). Further, there is also known an illumination device that determines a character size or color/monochrome to adjust light (see, for example, patent document 3).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. H04-144002

Patent document 2: japanese patent laid-open publication No. 2013-125596

Patent document 3: japanese patent laid-open No. 2014-086311

Disclosure of Invention

Problems to be solved by the invention

In the above-described lighting device, there are the following problems. That is, it is not considered that the posture of the user is various and constantly changed. When the posture is changed, the positional relationship with the table or the light source is also changed. Therefore, when the user reads a book, a state in which the distance between the eyes and the object such as a book on the desk is short may continue. As a result, the ciliary muscle of the eyeball is tensed, and this may cause a decrease in vision. Further, if the illuminance difference on the desk increases, a burden is imposed on the eyes, and this also causes a reduction in eyesight. Further, when the book is shaded with stationery or the user's hand, reading and recognition of characters and the like becomes difficult, and there is a possibility that the eyesight is also deteriorated. Further, when the illuminance on the desk is low, the user may read with the eyes close to the book or the like, and the distance between the eyes and the object becomes short as described above, which may lead to a reduction in eyesight.

Accordingly, an object of the present invention is to provide an illumination device that can illuminate a table with appropriate illuminance while maintaining an appropriate distance between the eyes of a user and an object.

Means for solving the problems

In order to solve the above problems and achieve the object, the lighting device of the present invention is configured as follows.

An illumination device, comprising: a light source for illuminating the table; an arm mechanism having a built-in motor for moving the position of the light source; detecting a user camera of a user; a table camera to detect a condition on the table; an image processing unit that calculates a distance from a specific part of a user to the table and a posture of the user based on a user image obtained by the user camera and a table image obtained by the table camera; a calculation unit that calculates an optimum light source position of the light source that minimizes a variance of the illuminance distribution, based on the posture of the user obtained by the image processing unit and the illuminance distribution obtained by the desktop camera; a warning unit that generates a warning when the distance is equal to or less than a predetermined value; and an arm control unit that operates the arm mechanism to move the light source to the optimal light source position.

Effects of the invention

According to the present invention, the user can irradiate the table with an appropriate illuminance while keeping an appropriate distance between the user's eyes and the object.

Drawings

Fig. 1 is a perspective view showing a lighting device and a table provided with the lighting device according to an embodiment of the present invention.

Fig. 2 is a perspective view showing the lighting device.

Fig. 3 is a bottom view showing the base assembled in the lighting device.

Fig. 4 is a block diagram showing a schematic configuration of the lighting device.

Fig. 5 is an explanatory diagram showing a mechanism model of the arm portion incorporated in the lighting device.

Fig. 6 is an explanatory diagram showing a basic operation flow of the lighting device.

Fig. 7 is an explanatory diagram showing an operation flow of mode selection of the lighting device.

Fig. 8 is an explanatory diagram showing an operation of detecting the distance between the eyes of the illumination device and the table.

Fig. 9 is an explanatory diagram showing an operation of detecting the distance between the eyes of the illumination device and the table.

Fig. 10 is an explanatory diagram illustrating a principle of detecting an illuminance distribution in the illumination device.

Fig. 11 is an explanatory diagram showing coordinate axes of the light source position of the lighting device.

Fig. 12 is an explanatory view showing an image and an illuminance histogram before improvement of the illuminance distribution of the illumination device.

Fig. 13 is an explanatory view showing an image and an illuminance histogram of the illumination apparatus after the illuminance distribution is improved.

Description of the reference numerals

10 Lighting device

20 base part

21 face camera (user camera)

30 arm mechanism

40 arm part

41 first arm

42 second arm

43 elevation angle adjusting component

44 head swinging component

45 lamp holder mounting part

50 arm action part

51 first motor

51a first angle sensor

52 second motor

52a second angle sensor

53 third motor

53a third angle sensor

54 fourth motor

54a fourth angular transducer

55 fifth motor

55a fifth angle sensor

56 sixth motor

56a sixth angle sensor

61 Lamp holder seat

62 light source

63. 64 desktop camera

65 illuminance sensor

100 control device

110 control part

120 image processing part

130 arithmetic device

140 warning unit

H users

D table

Detailed Description

Fig. 1 is a perspective view showing an illumination device 10 according to an embodiment of the present invention and a table D provided with the illumination device 10. Fig. 2 is a perspective view showing the lighting device 10. Fig. 3 is a bottom view showing the base 60 assembled in the lighting device 10. Fig. 4 is a block diagram showing a schematic configuration of the lighting device 10. Fig. 5 is an explanatory diagram showing a mechanism model of the arm portion 40. Fig. 6 is an explanatory diagram showing a basic operation flow of the lighting device 10. Fig. 7 is an explanatory diagram illustrating an operation flow of mode selection of the lighting device 10. Fig. 8 is an explanatory diagram illustrating an operation of detecting the distance between the eyes of the illumination device 10 and the desk. Fig. 9 is an explanatory diagram illustrating an operation of detecting the distance between the eyes of the illumination device 10 and the desk. Fig. 10 is an explanatory diagram illustrating the principle of detecting the illuminance distribution of the illumination device 10. Fig. 11 is an explanatory diagram showing coordinate axes of the light source positions of the lighting device 10. Fig. 12 is an explanatory view showing an image and an illuminance histogram before improvement of the illuminance distribution of the illumination device 10. Fig. 13 is an explanatory view showing an image and an illuminance histogram after improvement of the illuminance distribution of the illumination device 10. Further, H in fig. 1 indicates a user.

The lighting device 10 includes: a base part 20 mounted on the table D; a fixing jig 25 for fixing the base part 20 to the table D; an arm mechanism 30 whose base end side is attached to the base portion 20 and which determines the position of the light source 62; and a base 60 provided on the front end side of the arm mechanism 30.

A control device 100, which will be described later, is provided in the base portion 20. A face camera (user camera) 21 is provided on the front side of the base unit 20, and the face camera 21 detects a specific part (for example, the position of the eyes) of the user H and the posture of the upper body of the user H and outputs a face image (user image). A mode switch 22 is provided on the upper surface of the base portion 20.

The arm mechanism 30 includes an arm portion 40 and an arm operating portion 50 that operates the arm portion 40.

The arm portion 40 includes: a first arm 41 provided on the rotary shaft 23 built in the base part 20 and rotating in the arrow α 1 direction in the figure; a second arm 42 provided on the tip end side of the first arm 41 so as to be rotatable about an axis in the horizontal direction; an elevation angle adjusting member 43 provided on the distal end side of the second arm 42 so as to be rotatable about an axis in the horizontal direction; a head swing member 44 rotatably provided on the elevation angle adjustment member 43; and a base attachment portion 45 provided to the head swing member 44 so as to be rotatable. The base 60 is attached to the base attachment portion 45.

The arm operating unit 50 includes: a first motor 51 and a first angle sensor 51a built in the base portion 20 for rotating the rotary shaft 23 in the direction of arrow α 1 in the figure; a second motor 52 and a second angle sensor 52a for rotating the first arm 41 in the direction of arrow α 2 in the figure; a third motor 53 and a third angle sensor 53a for rotating the second arm 42 in the direction of arrow α 3 in the figure; a fourth motor 54 and a fourth angle sensor 54a for rotating the elevation angle adjustment member 46 in the direction of arrow α 4 in the figure; a fifth motor 55 and a fifth angle sensor 55a for rotating the swing head member 44 in the direction of arrow α 5 in the figure; and a sixth motor 56 and a sixth angle sensor 56a for rotating the base attachment portion 45 in the direction of arrow α 6 in the figure.

The arm mechanism 30 operates the arm operating unit 50, thereby performing various controls on the position and the irradiation direction of the light source 62 described later, and for example, can move the light source to an optimal light source position.

The base 60 includes: a rectangular base 61; a light source 62 disposed on the lower surface of the base 61 for illuminating the desk D; desk cameras 63 and 64 provided on the light source 62 side and detecting the illuminance distribution on the desk and outputting desktop images; and an illuminance sensor 65 provided on the upper surface of the base 61 for detecting an environmental condition.

The control device 100 includes: a control unit 110 for controlling the arm unit 30 while cooperatively controlling the respective units; an image processing unit 120 connected to the control unit 110; an arithmetic device (arithmetic unit) 130; and a warning unit 140 that warns the user H with sound or light when the distance between the eyes and the table is equal to or less than a predetermined distance (threshold value).

The image processing unit 120 is connected to the output of the face camera 21 and the outputs of the table cameras 63 and 64, processes the face image obtained by the face camera 21 and the table images obtained by the table cameras 63 and 64, detects position data of a specific part of the user H (here, the eyes of the user H), and calculates the distance Q between the eyes of the user H and the table D and the posture of the user H.

The arithmetic device 130 calculates an optimum light source position of the light source 62 that minimizes the shadow of the user H and minimizes the illuminance difference on the table D by minimizing the variance of the histogram of the illuminance distribution on the table D based on the posture of the upper body of the user H.

The warning unit 140 has a function of warning by sound or light when the distance Q from the eyes of the user H to the table D is less than a reference value (predetermined value). Specifically, a warning sound from a speaker, blinking of the light source 62, or the like is used.

The lighting device 10 configured as described above is used as follows. The lighting device 10 is provided with, for example, the following four modes. Namely (M1) standby mode, (M2) calibration mode, (M3) light source position control mode, and (M4) hand concentrating mode. These modes are sequentially switched as shown in fig. 7 by pressing the mode switch 22.

(M1) Standby mode

The standby mode is a mode in which standby processing of the lighting device 10 is executed. And switching to the standby mode after the power is turned on. When the arm mechanism 30 is in the standby mode, the light source 62 is not turned on.

(M2) calibration mode

The calibration mode is a mode for adjusting the face camera 21 and the table cameras 63 and 64. In general, the transition to the calibration mode is performed only once when the power is turned on for the first time, and the calibration mode can be entered by an arbitrary operation. The adjustment of the face camera 21 and the table cameras 63 and 64 is to perform image learning of the face, upper body, eyes, and hands of the user H, and calculate a conversion coefficient to length based on pixels of a dedicated template (pattern sheet).

(M3) light source position control mode

The light source position control mode is a mode for controlling the position of the light source 62 of the lighting device 10 in accordance with the posture of the user H and the environmental conditions. The mode switch is selectively switched to the light source position control mode by the operation of the mode switch by the user H. The control method will be described later.

(M4) hand-side concentration mode

The hand concentrating mode is a mode in which the light of the lighting device 10 is controlled so as to be always irradiated to the hand of the user H. By operating the mode switch 22, the mode is selectively switched to the hand-side concentration mode. While staying in the hand-concentrating mode, the lighting device 10 recognizes the position of the hand of the user H by the table cameras 63, 64. The lighting device 10 controls the arm mechanism 30 so that the hand of the user H moves to the center of the image obtained by the table top cameras 63, 64. Thereby, the periphery of the hand of the user H is irradiated.

By providing these four modes, as shown in fig. 6, after the power-on start, the operation modes (M1) to (M4) are selected by the mode switch 22 (ST 10). Then, the selected operation modes (M1) to (M4) are executed (ST11), and the power supply is turned off, whereby the operation is terminated.

More specifically, the operation modes (M1) to (M4) are switched each time the mode switch 22 is pressed. Fig. 7 shows this flow of actions. That is, after the start, it is determined whether or not the mode switch 22 is pressed (ST 20). If not pressed, the standby mode is continued (M1) (ST 21). If pressed, it is judged whether or not the calibration is completed (ST30), and if so, it proceeds to ST 40.

If the calibration is not completed, the calibration mode (M2) is executed (ST31), and it is judged whether the calibration is normally executed (ST32), and if it is normally completed, ST40 is entered. Further, if not completed, return is made to ST 31.

ST40 shows a light source position control mode (M3). It is judged whether or not the mode switch 22 is pressed (ST41), and the light source position control mode is continued until pressed (M3). When pressed, the mobile terminal enters the hand-focusing mode (M4) (ST 50).

Subsequently, it is determined whether or not the mode switch 22 is pressed (ST51), and the hand focusing mode is continued until the mode switch is pressed (M4). And ending when the button is pressed.

Next, the light source position control mode will be described in detail. Upon switching to the light source position control mode, an image of the user H is acquired by the face camera 21. The image processing unit 120 of the illumination device 10 has an image recognition function realized by software created using a Haar-like feature obtained in advance based on images of a plurality of eyes and an AdaBoost algorithm. In addition, a large amount of data of the posture of the person, the shape of the hand, and the like are input to perform image recognition. By applying the acquired image to the image processing section 120, the position of the eye on the image is found.

The position coordinates of the eyes are set to Ex and Ey. Further, since the position of the face camera 21 is set so that the lowest part of the image that can be acquired has the same height as the upper surface of the table D, the lowest part of the image can be adopted as the position of the table D. Therefore, the height of the eye position detected as described above is directly used as the distance from the eye to the table D. Thus, the posture is considered to be deteriorated when the following expression is satisfied.

Ey＜Eth…(1)

Where Eth is a posture deterioration warning threshold.

When the arithmetic device 130 detects that the posture of the user H is deteriorated, the lighting device 10 warns the user H with sound, light, or the like through the warning unit 140.

Fig. 8 and 9 show the relationship between Ex and Ey when the face camera 21 recognizes the coordinates of the positions of the eyes of the user H. The position coordinates of the eye are expressed by (Ex, Ey). The posture deterioration warning threshold is set to Eth 300. As shown in fig. 8, in the case where the posture of the user H is normal, the position coordinates of the eyes obtained by the image processing are (Ex, Ey) ═ (310, 400). Thus, the distance between the eye and the table is 400, and since it is higher than the threshold value, no warning is issued.

On the other hand, as shown in fig. 9, when the posture of the user H is deteriorated and the position coordinates of the eyes obtained by the image processing are (Ex, Ey) — (90, 260), the distance between the eyes and the table is 260, and a warning is issued because the distance is below the threshold.

Next, a procedure is shown in which the lighting device 10 performs control to move to a light source position that can reduce illuminance unevenness based on the current lighting condition observed by the lighting sensor 65.

Fig. 10 illustrates an illuminance distribution detection principle. That is, the illuminance distribution in the use environment is measured, and the estimated illuminance distribution detected at the viewpoint position (Hi) of the user H is obtained. Based on the estimated illuminance distribution, an optimum position of the light source that can reduce the illuminance unevenness is calculated.

The optimal position of the light source 62 is set as a target position, a movement locus of the tip end of the arm mechanism 30 is generated, and the light source position is moved to the optimal position by locus tracing control.

The lighting device 10 measures the illuminance distribution Ia (i, j) on the plane of the table D using the table top cameras 63, 64. Next, an estimated illuminance distribution Ib at the viewpoint position of the user is obtained based on the following equation.

Ib＝RXuIa…(2)

Where R is a transformation matrix based on the illumination distribution coordinate system, Xu is the viewpoint space coordinate of the user H, and Ia is the illumination distribution. The viewpoint space coordinates Xu of the user H [ x, y, z, θ r, θ p, θ y ] are acquired by detecting the eyeball position by image processing based on the acquired image of the face camera 21 and detecting the position in the depth direction based on the depth data.

The light source position with less illuminance unevenness is obtained by using the estimated illuminance distribution Ib. Therefore, the illumination model Im of the illumination apparatus 10 is used. This is modeled from the viewpoint of how much influence is exerted on the illuminance distribution at the current user viewpoint position. The illuminance distribution received by the end user in consideration of the lighting model is denoted by "model-considered illuminance distribution" and Ic. The relationship between the illuminance distribution Ib and the illumination model Im, model-considered illuminance distribution Ic is estimated as the following expression.

Ic＝Ib－Im…(3)；

The illumination model Im (x, y, z) is expressed as follows.

Im＝SXKL+CX…(4)；

Wherein, S is a coordinate transformation matrix from the light source to the viewpoint position of the user, X is the position coordinate of the light source, K is a model correction coefficient matrix, L is the illumination intensity distribution of the upper surface of the table, and C is a correction term.

In the present method, the light source position where illuminance unevenness is small is regarded as a position where the model considers that the illuminance distribution is uniform at any position. Namely, the following light source positions are provided: when the histogram h (n) (illuminance value-to-frequency) of the illuminance distribution is considered in the rendering model, the light source position is a curve approximate shape having a high sharpness where a certain value has a peak. In order to determine the light source position, the light source position is optimized by a gradient method. The evaluation function at this time is for the histogram h (n):

[ mathematical formula 1]

s.t.n∈Z

WhereinM is the number of illumination data, h_aIs the average value of illuminance, h_iIs an illuminance value, and Z is a set of illuminance data. The evaluation function means that the maximization of a spatial region having a specific luminance on the luminance distribution is achieved by the minimization of the variance of the histogram h (n).

Fig. 11 is a coordinate axis showing the light source position of the lighting device 10. In the light source position control mode, the light source positions (xc, yc, zc, θ rc, θ pc, θ yc) with small illuminance unevenness can be obtained by the above-described optimization calculation. In order to set the light source position to (xc, yc, zc, θ rc, θ pc, θ yc), the movement locus of the base 60 (the arm tip) is generated and tracking control is performed. Thereby, the light source 62 is moved to (xc, yc, zc, θ rc, θ pc, θ yc). Thus, the lighting device 10 moves to the optimal light source position based on the current lighting situation observed, and the lighting environment on the desk D with less illuminance unevenness can be realized. In addition, not only by controlling the light source position, but also by controlling the illuminance and color temperature of the light source 62 itself, a lighting environment with less illuminance unevenness can be realized.

Fig. 12 and 13 are explanatory views of an image showing the process of improving the illuminance distribution obtained as described above and a histogram of the illuminance distribution obtained by processing the image. That is, based on the images obtained by the desktop cameras 63 and 64, a histogram of the illuminance distribution shown in the graph of fig. 12 before improvement is obtained. The histogram has a large variance, and thus, the illuminance is not uniform. The light source position coordinate at this time is (x, y, z, θ r, θ p, θ y) — (100, 200, 300, 0, 0, 0).

Next, the calculation device 130 calculates the optimal light source position without uneven illuminance based on the above equation (5). The result of the calculation is, for example, (xc, yc, zc, θ rc, θ pc, θ yc) ═ (82, 98, 312, pi/6, -pi/12, 2 pi/12). The arm mechanism 30 is actuated and moved so that the light source 62 is located at that position. The illuminance distribution after the shift is an ideal illuminance distribution in which the central portion is brightest and gradually becomes darker as going to the periphery, as shown in fig. 13.

As described above, according to the lighting device 10 of the present embodiment, when the distance between the eyes of the user H and the table D is equal to or less than the predetermined value, a warning is issued so as to ensure that the distance between the eyes of the user H and the table D does not excessively approach. Further, in the case where the illuminance distribution on the table D is inappropriate, the light source 62 can be moved to improve the illuminance distribution to illuminate the table with appropriate illuminance. Therefore, the visual deterioration of the user H can be prevented.

The present invention is not limited to the above embodiments. The specific part imaged by the face camera may be a part of the upper body other than the eyes, for example, a part capable of predicting the position of the eyes such as the position of the ears, and is not limited to the eyes. It is apparent that various modifications can be made within a scope not departing from the gist of the present invention.

Claims (5)

1. An illumination device is characterized by comprising:

a light source for illuminating the table;

an arm mechanism having a built-in motor for moving the position of the light source;

detecting a user camera of a user;

a table camera that detects an illuminance distribution on a table;

an image processing unit that calculates a distance from a specific part of a user to the table and a posture of the user based on a user image obtained by the user camera and a table image obtained by the table camera;

a calculation unit that calculates an optimum light source position of the light source that minimizes a variance of the illuminance distribution, based on the posture of the user obtained by the image processing unit and the illuminance distribution obtained by the desktop camera;

a warning unit that generates a warning when the distance is equal to or less than a predetermined value; and

an arm control unit that operates the arm mechanism so that the light source is moved to the optimal light source position.

2. A lighting device as recited in claim 1, wherein:

an illuminance sensor for detecting an environmental condition is provided,

the calculation unit calculates an optimum light source position of the light source that minimizes a variance of the illuminance distribution based on the posture of the user determined by the image processing unit, the illuminance distribution obtained by the desktop camera, and the detection result of the illuminance sensor.

3. An illumination device is characterized by comprising:

a light source for illuminating the table;

detecting a user camera of a user;

an image processing unit that calculates a distance from a specific part of the user to the table based on the user image obtained by the user camera; and

and an alarm unit that generates an alarm when the distance is equal to or less than a predetermined value.

4. An illumination device is characterized by comprising:

a light source for illuminating the table;

an arm mechanism having a built-in motor for moving the position of the light source;

detecting a user camera of a user;

a table camera for detecting an illuminance distribution on the table;

an image processing unit that calculates a posture of the user based on the user image obtained by the user camera and the desktop image obtained by the desktop camera;

a calculation unit that calculates an optimum light source position of the light source that minimizes a variance of the illuminance distribution, based on the posture of the user obtained by the image processing unit and the illuminance distribution obtained by the desktop camera; and

an arm control unit that operates the arm mechanism so that the light source is moved to the optimal light source position.

5. A lighting device as recited in claim 4, wherein:

an illuminance sensor for detecting an environmental condition is provided,

the calculation unit calculates an optimum light source position of the light source that minimizes a variance of the illuminance distribution based on the posture of the user determined by the image processing unit, the illuminance distribution obtained by the desktop camera, and the detection result of the illuminance sensor.