JP5177489B2 - LED illumination light source device - Google Patents

Description

  The present invention relates to an LED illumination light source device. More specifically, the present invention is an LED illumination light source device that is particularly suitable for observing the difference in the appearance of an object to be measured.

In the manufacture of many products and the like, it is important to maintain a certain color, gloss, or surface condition (attachment of scratches, dust, etc.). However, there are many cases where the color luster differs depending on the temperature, humidity, product shape, etc. at the time of product manufacture.
Even when the same object is irradiated with the same illumination light and viewed with an imaging member such as a camera or the like, the observation direction of the object to be observed, the direction of the installation position of the object to be observed, and the illumination angle of the illumination light Differences may appear in the appearance due to differences. For example, a cloth or the like may have directionality in its weaving method, and the texture may be observed with a considerably different texture depending on the viewing direction. Conversely, although there is a difference in color luster depending on the color and intensity of the illumination light, the difference may not be detected depending on the illumination light illuminance and color.

  Up to now, various proposals have been made for observing the surface state, color, scratches, and the like of products to perform quality control and accurate reading of required product data (Patent Documents 1 to 5). Some of these have been proposed using LEDs. This LED has an advantage that the cost is low and the lighting device can be manufactured at a lower cost.

On the other hand, in homes, stores, showrooms and the like, there are not a few requests for warming the lighting, giving it a refreshing feeling, and performing lighting with variations.
JP 2001-183304 A JP 2005-195444 A JP-A-5-332939 JP 2000-55820 A

However, visually while illuminating the object to be measured such as the product by the illumination device, when the observation of the object to be measured, subtle differences in in adaptation eye illuminating light by a special structure or local gloss Or the difference in texture may not be discernible. In addition, due to differences in lighting conditions, not only visual observation but also observation of an object to be measured using an imaging means such as a camera makes it impossible to detect subtle differences in local color gloss or differences in texture. There is.

  The present invention has been made in view of the actual situation of the prior art, and more accurately discriminates or detects a subtle difference in local color gloss or a difference in texture due to a special structure of an object to be measured. It is an object of the present invention to provide an LED illumination light source device that can be used.

  In addition, the present invention performs illumination with variations that can make the illumination light invisible or have an invisible cooling sensation in homes, stores, showrooms, etc. It is also an object to provide an LED illumination light source device that can be used.

  In order to solve the above problems, according to the present invention, the following technical means are provided.

[1] An LED light source composed of a blue LED, a red LED, a green LED, and a white LED, a pulse control circuit for steady light that controls the LED light source with a PWM pulse drive current having a time width of 10 μs to 1 ms, and the LED light source From a pulse control circuit for light that is controlled by a PWM pulse driving current having a time width of 10 to 30 ms, which is a period that does not make the viewer feel blinking, and from the pulse control circuit for steady light that is controlled by a time width of 10 μs to 1 ms LED light source drive for driving the LED light source with a PWM pulse drive current obtained by superimposing a PWM pulse drive current on the time axis and a PWM pulse drive current from the light pulse control circuit controlled with a time width of 10 to 30 ms. comprising a circuit, and the blue LED, a red LED, a period of time in the range of 10~30ms the light intensity of the green LED and white LED In LED illumination light source device characterized by varying independently.

[2] The LED illumination light source device according to the first invention, wherein the time width can be adjusted in a plurality of stages within the range of the intensity of the steady light within a range of 10 μs to 1 ms .

[3] The LED illumination light source device according to the first or second invention, wherein the LED illumination light source device irradiates illumination light in order to observe the object to be measured visually or by an imaging means .

[4] The LED illumination light source device according to the third aspect , wherein the object to be measured can be observed by changing at least one of the illuminance and color of the illumination light.

[5] The LED illumination light source device according to the third or fourth aspect of the invention, further comprising means for changing the illumination angle of the illumination light, wherein the object to be measured can be observed by changing the illumination angle of the illumination light. .

[6] The LED illumination according to any one of the third to fifth aspects, further comprising means for changing the angle of the object to be measured, and observing the object to be measured by changing the angle of the object to be measured. Light source device.

[7] The LED illumination light source device according to any one of the third to sixth aspects, wherein the object to be measured can be observed by changing the irradiation direction of the illumination light to the object to be measured in the entire space .

  According to the present invention, since the above technical means is adopted, it is possible to more accurately discriminate or detect a subtle difference in local color gloss or a difference in texture due to a special structure of the object to be measured. It becomes. In particular, in visual observation, adaptation to eye illumination light can be inhibited by illumination light including light that does not cause blinking in the eyes, and the discrimination and detection effects can be further improved.

  In addition, the present invention performs illumination with variations that can make the illumination light invisible or have an invisible cooling sensation in homes, stores, showrooms, etc. Therefore, its application range is wide.

  Hereinafter, embodiments of the present invention will be described in detail.

  1A and 1B are diagrams showing an LED illumination light source unit 11 of an LED illumination light source device according to an embodiment of the present invention, where FIG. 1A is a plan view and FIG. 1B is a side view. FIG. 2 is a diagram showing a control circuit system of the KED illumination light source device of the embodiment.

  The LED illumination light source unit 11 according to the present embodiment includes seven LEDs, which are two blue LEDs 12a, two red LEDs 12b, two green LEDs 12c, and one white LED 12d. 12c is arranged. Reference numeral 13 denotes a fixing tool such as a screw. In this example, two blue, red, and green LEDs 12a to 12c are arranged around one white LED. However, the number and arrangement of these LEDs are not limited to this example, and can be arbitrarily set.

  As shown in FIG. 2, the LEDs 12a to 12d are driven and controlled by a steady light pulse control circuit 14, a light pulse control circuit 15 controlled by a PWM pulse drive current having a time width of 10 to 30 ms, and an LED light source drive circuit 16. Is done.

  The steady light pulse control circuit 14 controls the LEDs 12 a to 12 d with a PWM pulse drive current having a time width of 10 μs to 1 ms. For example, if it is changed every 10 μs, the light intensity control of stationary light (substantially continuous light) in 100 steps can be performed. Of course, the number of steps can be arbitrarily set. The output intensity of the steady light from each of the LEDs 12a to 12d can be changed independently. The steady light irradiated to the object to be measured is obtained by adding the light outputs of the LEDs 12a to 12d of the LED illumination light source unit 11 together. The illuminance and color of steady light (the illuminance ratio of R, G, B, and W) can be performed by controlling the known duty ratio. If the pulse width of the PWM pulse output by the steady light pulse control circuit 14 is shorter than 10 μs, the number of gradations of the LED output becomes 100 or more, and the burden on the digital circuit of the control system becomes large. The number of gradations becomes 1 or less, and color light control becomes impossible.

  The light pulse control circuit 15 that controls the PWM pulse drive current having a time width of 10 to 30 ms controls the LEDs 12a to 12d with the PWM pulse drive current having a time width in the range of 10 to 30 ms. Pulse light having a time width in this range is a period in which the eyes do not feel blinking, and gives a specific effect. When the time width of the PWM pulse driving current output from the light pulse control circuit 15 is shorter than 10 ms, the light is not visually recognized, and when it is longer than 30 ms, the light is always recognized by the consciousness.

  The light intensity of each of the LEDs 12a to 12d can be changed independently with a time width within a range of 10 to 30 ms. Also in this case, the light irradiated to the object to be measured is the sum of the light outputs of the LEDs 12a to 12d of the LED illumination light source unit 11. By independently controlling the light intensity of each of the LEDs 12a to 12d, it is possible to change the light presentation color. It can also be changed by controlling the duty ratio. The application operation of turning on and off the pulsed light brings about a novel lighting effect that affects the “human appearance”.

  Illumination light by the LED illumination light source device of this embodiment is obtained by adding light controlled by a PWM pulse having a time width of 10 to 30 ms to stationary light.

  The LED illumination light source device according to the present embodiment can be suitably used for observing the surface condition such as color gloss, scratches, dust adhesion, etc. of an object to be measured such as various products. In this case, due to the effect of light controlled by PWM pulses with a time width of 10 to 30 ms, it is possible to reliably detect subtle differences in local color gloss due to special structures in visual observation or observation with an imaging member such as a camera. become able to.

  According to the LED illumination light source device of the present embodiment, the object to be measured can be observed by changing at least one of the illuminance and color of the illumination light.

  In addition, the LED illumination light source device of the present embodiment can also observe the object to be measured by changing the irradiation angle of the illumination light using a known rotating means.

In addition, the LED illumination light source device according to the present embodiment can observe the object to be measured by changing the angle of the object to be measured by providing means for changing the angle of the object to be measured such as a rotatable support plate. it can. By arbitrarily selecting multiple LED illumination light source units that can be attached to the inner wall surface of a hemispherical dome-shaped device as described later and output illumination light, the illumination light irradiation direction on the object to be measured can be changed throughout the space. Thus, the object to be measured can be observed.
In this way, in addition to the above functions, (1) the light irradiation angle can be changed continuously or discretely, (2) the number and location of light emitting points can be changed, (3) chromatic adaptation transition It is possible to provide such a performance that can be prevented.

Furthermore, the LED illumination light source device of the present invention can be applied to illumination in homes, shops, and showrooms. In that case, for example, it is possible to present common information to a color blind person and a healthy person, and it is invisible to illumination light by light controlled by a red PWM pulse having a time width of 10 to 30 ms. It is possible to make the illumination light invisible to the illumination light by the blue light , to inhibit the adaptation function of the eye by the effect of the light.

  Next, examples of the present invention will be described.

  FIG. 3 is an example in which the LED illumination light source device of the present invention is applied to a hemispherical dome-shaped device 21, and FIG. 3B is a cross-section when FIG. 3A is rotated 90 degrees in the in-plane direction. FIG. Although two LED illumination light source units 22 and 23 are provided in FIG. 3 for illustration, it is possible to install a large number of them by changing the latitude and longitude in addition to those shown in this embodiment. The structure of the LED illumination light source unit 22 can be the same as that shown in FIG. In the LED illumination light source units 22 and 23 of FIG. 3, the rotation range is set to 30 °. Control of each LED in the LED illumination light source units 22 and 23 can be performed by a control circuit system as shown in FIG. In FIG. 3, two pairs (22 and 23) of two LED illumination light source units are provided, and the structure of the LED illumination light source units 22 and 23 is the same as that shown in FIG.

  In this embodiment, the measurement is performed by visual observation or an imaging member such as a camera from the flat portion 24 on the upper surface of the hemispherical dome-shaped device 21. The flat part 24 may be an opening, or a transparent plate may be provided so that it can be observed. Reference numeral 25 denotes a base. In this example, the dome radius of the hemispherical dome-shaped device 21 is 180 mm, the radius of the base 25 is 210 mm, and the LED illumination light source units 22 and 23 have their LED tips at a radius of 150 mm. The movable range (shown by hatching in the figure). Is centered at a position of 45 degrees from the center of the upper surface of the base 25.

  According to the hemispherical dome-shaped device 21 of this embodiment, observation and measurement similar to those described in Patent Documents 1 to 5 can be performed. Observe by changing the illuminance and color (illuminance ratio of R, G, B, and W) of the illumination light, observe the difference in texture of the object to be measured (such as fabric and paint), and the illumination light irradiation angle The observation direction can be changed by changing the irradiation direction or the angle or rotation direction of the object to be measured.

When a silk cloth was placed on the base 25, the LED illumination light source units 22 and the LED illumination light source units 23 were alternately turned on and observed from the flat portion 24, a difference in texture was observed. The observation area is 50 mm square. The difference in texture was observed differently depending on the color of the illumination light. The appearance was clearly different depending on the irradiation direction. By selecting the color of the illumination light optimally, it was more prominent than under natural light, fluorescent light, or bulb light. Also, as a result of observation by the imaging member such as a camera, the difference in texture, as shown in FIGS. 4-7 were taken differently by the color of the illumination light.
FIG. 4 is a view showing a silk cloth photographed from directly above under room illumination (x = 0.376, y = 0.391, 600 lx). 5, FIG. 6 and FIG. 7 are diagrams showing silk cloths obtained by photographing the LED illumination light source unit 22 and the LED illumination light source unit 23 alternately. In FIG. 5, the light color is D65 daylight color light (combined light of four kinds of LEDs: x = 0.29, y = 0.30, 250 lx), and the right side is FIG. 3A and the left side. Is the irradiation in the state of FIG. In FIG. 6, green LED light (x = 0.18, y = 0.75, 250 lx) is irradiated, and the right side is irradiation in the state of FIG. 3A and the left side is the state of FIG. 3B. In FIG. 7, blue LED light (x = 0.14, y = 0.07, 35lx) is irradiated, and the right side is irradiated in the state of FIG. 3 (a) and the left side is irradiated in the state of FIG. 3 (b). . FIG. 8 illustrates these lights in terms of chromaticity.

  In this example, it was proved that the difference in texture can be remarkably discriminated by changing the illumination light irradiation direction and color while the observation object is fixed.

  Conventionally, in order to determine the color and texture of an object, generally, there are many methods of working under natural light such as north window light in fine weather. On the other hand, in the above-described embodiment, it is possible to easily perform the determination work under various suitable light including light similar to natural light regardless of the weather, season, and time.

It is a figure which shows the LED illumination light source unit 11 of the LED illumination light source device which concerns on one Embodiment by this invention, (a) is a top view, (b) is a side view. It is a figure which shows the control circuit system of the LED illumination light source device of the embodiment. It is sectional drawing which shows the Example which applied the LED illumination light source device of this invention to the hemispherical dome shape apparatus 21. FIG. It is a figure which shows the silk cloth image | photographed from right above under room lighting. It is a figure which shows the silk cloth which image | photographed the LED illumination light source unit of Fig.3 (a) and the LED illumination light source unit of FIG.3 (b) alternately, and irradiated and irradiated the light of D65 daylight color. It is a figure which shows the silk cloth image | photographed by alternately lighting the LED illumination light source unit of Fig.3 (a) and the LED illumination light source unit of FIG.3 (b), and irradiating green LED light. It is a figure which shows the silk cloth image | photographed by alternately lighting the LED illumination light source unit of Fig.3 (a) and the LED illumination light source unit of FIG.3 (b), and irradiating blue LED light. The coordinates of the light used in FIGS. 4 to 7 are shown on the chromaticity diagram.

11 LED illumination light source unit 12a Blue LED
12b Red LED
12c Green LED
12d white LED
14 Pulse control circuit for stationary light 15 Light control circuit controlled by PWM pulse drive current having a time width of 10 to 30 ms 16 LED light source drive circuit 21 Hemispherical dome-shaped device (LED illumination light source device)
22, 23 LED illumination light source unit 24 Flat part 25 Base

Claims (7)

An LED light source comprising a blue LED, a red LED, a green LED and a white LED;
A steady light pulse control circuit for controlling the LED light source with a PWM pulse drive current having a time width of 10 μs to 1 ms;
A light pulse control circuit that controls the LED light source with a PWM pulse driving current having a time width of 10 to 30 ms, which is a period in which the viewer does not feel blinking ;
The PWM pulse drive current from the light pulse control circuit controlled by the time width of the PWM pulse driving current and 10~30ms from the fixed light pulse control circuit controlled by the duration of 10μs~1ms time axis an LED light source driving circuit for driving the LED light source in the PWM pulse driving current overlapped, and,
An LED illumination light source device , wherein the light intensity of each of the blue LED, red LED, green LED, and white LED is independently changed over a time width within a range of 10 to 30 ms . 2. The LED illumination light source device according to claim 1 , wherein the time width can be adjusted in a plurality of stages within the range of the intensity of the steady light of 10 μs to 1 ms . The LED illumination light source device according to claim 1 or 2 , wherein the LED illumination light source device irradiates illumination light in order to observe the object to be measured visually or by an imaging means . The LED illumination light source device according to claim 3 , wherein the object to be measured can be observed by changing at least one of the illuminance and color of the illumination light. 5. The LED illumination light source device according to claim 3 , further comprising means for changing an irradiation angle of the illumination light, wherein the object to be measured can be observed by changing the irradiation angle of the illumination light. 6. The LED illumination light source device according to claim 3 , further comprising means for changing the angle of the object to be measured, wherein the object to be measured can be observed by changing the angle of the object to be measured . The LED illumination light source device according to any one of claims 3 to 6, wherein the object to be measured can be observed by changing the irradiation direction of the illumination light to the object to be measured in the entire space .