JPH11232912A - Led illuminating structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small structure, which consumes less electric power and can reduce unevenness in light quantity by arranging LEDs into an array form and arranging a light guide body for converging/diffusing light beams on the top part of the LEDs. SOLUTION: Chip type LEDs 1, serving as light sources for illuminating an object to be projected, are arranged into an array form on a printed wiring board 10, and in the predetermined position on the top part of the LEDs 1, a light guide body 2, which is constructed of an elliptic columnar type convex lens 11 and a prism type concave lens 12 and effective in converging and/or diffusing light beams emitted from the LEDs 1, is arranged. In this way, the light emitted from a point light source is converged by a short focal length convex lens 11, and then is diffused by means of the concave lens 12 so as to be turned into the light similar to that from a surface light source, so that unevenness in light quantity can be reduced despite a short optical path length. Because of reduction in a space for the LED and the energy-efficient light source, a small structure which consumes less electric power can be attained. Alternatively, when the upper part of the concave lens 12 in the light guide body 2 is formed into a tooth type shape longitudinally, unevenness of quantity of light can be further reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating light to a surface of a subject such as an image scanner or an OCR of an information processing apparatus, receiving reflected light from the surface of the subject, and converting image and character information into electric signals. The present invention relates to an LED illumination structure which is a means for illuminating a subject in a reading device, and relates to the realization of an LED illumination structure which is small in size, consumes less power, and can reduce uneven light quantity.

[0002]

2. Description of the Related Art A conventional LED lighting structure shown in a side view of FIG. 9A and a front view of FIG. 9B uses an LED having a large space-saving and energy-saving effect. To illuminate the surface of a subject, such as an OCR or OCR, to convert the image or text information into an electrical signal and read it, in order to bring the illumination structure to the subject closer to the ideal light source, such as a hot cathode discharge lamp or other surface light source A light converging body composed of, for example, a columnar convex lens 52 having an effect of converging light emitted from the LEDs 51 is formed at a predetermined position above a chip-shaped LED 51 arranged in an array on a printed wiring board 53, Thus, the shortage of the amount of light emitted from the LED 51 by converging the light of the point light source has been compensated. However, the light of the point light source, which is emitted from the LED 51 and converges on the subject 54, is a convergent light portion 55 that is at the focal position of the cylindrical convex lens 52.
Is a portion where the amount of light is the highest, and there is a large difference in the amount of light from the diffused light portion 56 which is deviated from the focal position.
4 As shown in the distribution diagram of the light amount exceeding the predetermined light amount applied to the surface, the light amount distribution state is bellows-like, and the light amount unevenness is far from the flat elliptical or rectangular light distribution of the ideal form. there were.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the following problems of the above-mentioned conventional LED lighting structure. The LED is used to illuminate the surface of a subject, such as an image scanner or OCR of an information processing device, to convert the image or character information into an electrical signal in order to approach an area light source such as a hot cathode discharge lamp, which is an ideal light source. An illumination structure for the object in the device for converting and reading is constituted by forming a light converging body including a cylindrical convex lens or the like for converging light emitted from the LED at a predetermined position above the LEDs arranged in an array on the printed wiring board. In addition, the light of the point light source is converged on the subject and the shortage of the amount of light emitted from the LED is compensated for. However, the light of the point light source converging on the subject emitted from the LED has the highest light intensity at the converging light portion at the focal position of the cylindrical convex lens, and has a large difference in light intensity with the diffused light portion deviating from the focal position. The state is a bellows-like state, and the amount of light quantity unevenness is far from the flat elliptical or rectangular light distribution of the ideal form, and the reading quality of image and character information is lowered.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a light derivative for converging and / or diffusing light is formed on an upper portion where LEDs are arranged in an array. By converging and / or diffusing the light of the LED light source by this means, a light source utilizing the space-saving and energy-saving effects of the LED can be obtained. There is also provided an LED lighting structure that can be a possible lighting structure.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, as shown in FIG.
A light derivative 2 having an effect of converging and / or diffusing light was formed on an upper portion where 1 was arranged in an array. By this means, a light source that makes use of the space-saving and energy-saving effects of the LED can be obtained, so that an effect that a small-sized illumination structure with low power consumption can be obtained can be obtained.

Next, as shown in FIG.
Was corrugated or tooth-shaped. By this means, LE
Since the light of the D light source is converged and the light of the LED light source is diffused in a waveform or a tooth-shaped portion in directions other than the vertical direction, an effect of providing an illumination structure with less uneven light amount is obtained.

Further, as shown in FIG.
Is a half mirror waveform or tooth shape. By this means, the light of the LED light source can be diffused in a waveform or a tooth-shaped portion other than in the vertical direction, and the reflected light from the subject can be reflected back to the subject to increase the diffusion effect. Get the action that can be.

Further, as shown in FIG. 4, the light derivative 2 has a shape having a light converging portion and a light converging portion. By this means, the light derivative can be integrated with the light converging portion and the light diffusing portion, so that an effect can be obtained in which a compact and low power consumption illumination structure having a simple configuration and few components can be obtained.

Next, as shown in FIG.
Is a cylindrical lens 4 having a light diffusing portion with the lens 3 on the LED 1 side or the subject 5 side. By this means, the light guide can be integrated with the light converging portion and the light diffusing portion, so that an effect that a compact and low power consumption illumination structure having a simple configuration and few components can be obtained.

Further, as shown in FIG.
Is a cylindrical lens 4 having a diffused portion of light whose surface is roughened on the LED 1 side or the subject 5 side. By this means, the processing of the light converging portion and the diffusing portion of the light derivative can be easily integrated, so that a simple structure, processing, and a lighting structure with a small size and low power consumption including few components can be provided. Get.

Further, as shown in FIG. 7, the light derivative 2 is a cylindrical lens 4 having a milky white filter 6 on the LED 1 side or the subject 5 side. By this means, the milky white filter portion is used as a light diffusion portion and the LED
Since the color correction on the side or the subject side can also be performed, an effect that the throughput can be increased as compared with the case where the color correction is performed by the electric circuit of the control unit is obtained.

Next, as shown in FIG. 8, the filter section 6 can be replaced for color correction on the LED 1 side or the subject 5 side. By this means, it is possible to easily switch the color correction on the LED side or the subject side, so that it is possible to easily cope with a case where a plurality of types of color corrections are performed by replacing the filter unit.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG.

Reference numerals used in the drawings of the embodiments according to the present invention shown in FIGS. 1 to 8 will be collectively described below. 1
Reference numeral denotes an LED serving as a light source for illuminating a subject in an image scanner or an OCR of an information processing apparatus. Reference numeral 2 denotes an optical derivative that converges and diffuses light through the light of the LED 1 that is a subject illumination light source in an image scanner or an OCR of an information processing apparatus. Reference numeral 3 denotes a lens for refracting light by the light derivative 2. Reference numeral 4 denotes a cylindrical lens having a columnar shape and a lens for refracting light by the light derivative 2. Reference numeral 5 denotes an object to be read, which forms an image or character information in an image scanner or an OCR of the information processing apparatus. Reference numeral 6 denotes a filter unit that performs color correction on the LED side or the subject side. Reference numeral 10 denotes a printed wiring board on which the LEDs 1 are arranged in an array. Reference numeral 11 denotes a convex lens that converges and refracts light with the light derivative 2. Reference numeral 12 denotes a concave lens that diffuses and refracts light with the light derivative 2. Reference numeral 13 denotes a latch mechanism that allows the filter unit 6 to be attached to and detached from the cylindrical lens 4.

FIGS. 1A and 1B are principle diagrams of the present invention, wherein FIG. 1A is a side view and FIG. 1B is a front view. In the figure, for example, a convex lens 11 having an effect of converging and / or diffusing light emitted from the LED 1 and a prismatic shape having an effect of converging and / or diffusing light emitted from the LED 1 are arranged at a predetermined position on a printed wiring board 10 in which chip-shaped LEDs 1 are arranged in an array. The optical derivative 2 composed of the concave lens 12 was formed. As a result, the light of the point light source converged by the short focal length convex lens can be diffused by the concave lens and brought closer to the surface light source to reduce unevenness in the light amount even if the light path length is short. Since the light source can be used as a light source, it is possible to provide a compact illumination structure with low power consumption.

FIG. 2 is a diagram showing an embodiment of the present invention.
Is a side view, and (b) is a front view. In the figure, LE
The light derivative 2 having the effect of converging and / or diffusing light emitted from D1 is formed, for example, by forming the upper part of a prismatic concave lens 12 into a tooth shape in the longitudinal direction. In addition, it is also preferable not to limit to a tooth profile but to make a waveform in a longitudinal direction. Thereby, the light of the LED light source is converged and the light of the LED light source is diffused in the longitudinal direction other than the vertical direction in the tooth-shaped or wave-shaped portion.

FIG. 3 is a diagram showing another embodiment of the present invention.
(A) is a side view, (b) is a front view. In the figure, the light derivative 2 having the effect of converging and / or diffusing light emitted from the LED 1 is formed, for example, by forming the upper part of a prismatic concave lens 12 into a tooth shape in the longitudinal direction, and making the surface of the tooth shape a half mirror. In addition, it is also preferable not to limit to a tooth profile but to make a waveform in a longitudinal direction. As a result, the light from the LED light source can be diffused in the longitudinal direction except for the vertical direction in the tooth-shaped or wave-shaped portion, and the reflected light from the subject can be reflected back to the subject to increase the diffusion effect. The lighting structure can be reduced.

FIG. 4 is another embodiment of the present invention.
(A) is a side view, (b) is a front view. In the drawing, the light derivative 2 is, for example, an elliptic columnar convex lens 11 having a concave lens 12 in which the cross section is elliptical and the upper part is not concave, and has a shape having a converging portion and a diffusing portion for light emitted from the LED 1. did. This allows the photo-derivative to
Since the elliptic cylindrical convex lens can be used as the light converging part and the part lacking the concave surface can be integrated as the diffusing part, it is possible to provide a compact, low power consumption lighting structure with a simple configuration and few components. . Note that the shape of the portion lacking the concave surface may be a step-like shape like a Fresnel lens.

FIG. 5 is a diagram showing another embodiment of the present invention.
(A) is a side view, (b) is a front view. In the same figure, the light derivative 2 is, for example, a columnar convex lens 11 having a concave cross-section with about half of the upper part having a circular cross section being positioned on the subject 5 side with the concave lens 12 portion of the concave portion being positioned on the subject 5 side. The lens 3 was a cylindrical lens 4 having a light diffusion portion. In addition, it is also preferable to position the concave lens 12 part of the part lacking the concave surface on the LED 1 side. This allows the optical derivative to be integrated with the cylindrical lens in the converging portion of the light and the concave lens portion lacking the concave surface as the diffusing portion, so that it is small in size with a simple configuration and few components, and has low power consumption. It can be a lighting structure. The shape of the portion lacking the concave surface may be a V-shaped groove.

FIG. 6 is a diagram showing another embodiment of the present invention.
(A) is a side view, (b) is a front view. In the same figure, the light derivative 2 is formed, for example, in a form in which the cross section is circular and about half of the upper part is flat, and the surface is roughened by sandblasting or the like, and the columnar convex lens 11 is The cylindrical lens 4 having a light diffusing portion was a columnar convex lens 11 having a shape in which a half of a circular cross-section was lacking in a plane, with the roughened surface positioned on the side. Note that it is also preferable to position the roughened surface on the LED 1 side. This makes it possible to increase the amount of light at the light converging part with a cylindrical lens, or to make the roughened part a diffuser part closer to the surface light source. A compact, low power consumption lighting structure consisting of processed and few parts can be achieved.

FIG. 7 is a diagram showing another embodiment of the present invention.
(A) is a side view, (b) is a front view. In the figure, the optical derivative 2 is, for example, a cylindrical lens 4 having a milky white filter section 6 in which a milky white filter section 6 is positioned on the subject 5 side in a form in which a cross section is circular and about half of the upper part is flat. did. In addition, it is also preferable to position the milky white filter part 6 on the LED 1 side. As a result, the milky white filter portion can be made closer to the surface light source as a light diffusion portion and the color correction on the object side or the LED side can be performed. Therefore, the throughput can be reduced as compared with the case where the color correction is performed by the electric circuit of the control unit. Can be enhanced. Note that the filter unit may have a concave lens function.

FIG. 8 is a diagram showing another embodiment of the present invention.
(A) is a side view, (b) is a front view. 7, a filter mechanism 6 shown in FIG. 7 is provided with, for example, a latch mechanism 13 that can be attached to and detached from the cylindrical lens 4 at both ends, and is replaceable for color correction on the subject 5 side. In addition, the above-described filter unit 6 is located on the
It is also preferable to perform color correction on the D1 side. This makes it easy to switch the color correction on the object side or the LED side. As described above, it is possible to easily cope with a plurality of types of color correction by replacing the filter unit.

[0023]

According to the present invention described above, the following effects can be expected.

First, a light derivative having an effect of converging and / or diffusing light was formed on an upper portion where LEDs were arranged in an array. This makes it possible to provide a light source that utilizes the space-saving and energy-saving effects of the LED, so that a small-sized lighting structure with low power consumption can be obtained.

Next, the light derivative was formed into a waveform or a tooth shape. This allows the light of the LED light source to converge,
Since the light from the LED light source is diffused in the waveform or the tooth-shaped portion in directions other than the vertical direction, in addition to the above-described effects, an illumination structure with less unevenness in light amount can be provided. As a result, it is possible to improve the reading quality of image and character information.

Further, the light derivative has a half mirror waveform or tooth shape. In this way, the light from the LED light source can be diffused in a waveform or tooth-shaped portion other than in the vertical direction, and the reflected light from the subject can be reflected back to the subject to increase the diffusion effect. An illumination structure with less light quantity unevenness can be obtained.

Further, the light derivative has a shape having a light converging portion and a light converging portion. With this, the light derivative can integrate the light converging portion and the light diffusing portion. In addition to the above-described effects, it is possible to provide a compact illumination structure having a simple configuration and a small number of components.

Next, the light derivative was a cylindrical lens having a light diffusion portion by a lens on the LED side or the object side. With this, the light derivative can integrate the light converging portion and the light diffusing portion. In addition to the above-described effects, it is possible to provide a compact illumination structure having a simple configuration and a small number of components.

Further, the light derivative is a cylindrical lens having a light diffusion part with a roughened surface on the LED side or the object side. This makes it possible to easily integrate the processing of the light converging part and the light diffusing part into the light derivative, so that in addition to the above-described effects, it is possible to provide a simple configuration, processing, and a small illumination structure including few components. .

Further, the light derivative is a cylindrical lens having a milky white filter on the LED side or the subject side. This makes it possible to perform color correction on the LED side or the subject side using the milky white filter unit as a light diffusion unit, so that in addition to the above-described effects, the throughput can be increased as compared with the case where color correction is performed by the electric circuit of the control unit. Can be.

Next, the filter section can be replaced for color correction on the LED side or the object side. With this,
Since the color correction on the LED side or the subject side can be easily switched, in addition to the above-described effects, it is possible to easily cope with a case where a plurality of types of color corrections are performed by replacing the filter unit.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is an embodiment diagram of the present invention.

FIG. 3 is another embodiment of the present invention.

FIG. 4 is another embodiment of the present invention.

FIG. 5 is another embodiment of the present invention.

FIG. 6 is another embodiment of the present invention.

FIG. 7 is a diagram showing another embodiment of the present invention.

FIG. 8 is another embodiment of the present invention.

FIG. 9 is a diagram showing an example of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED 2 Light derivative 3 Lens 4 Cylindrical lens 5 Subject 6 Filter part

Claims (8)

[Claims] 1. An LED lighting structure, wherein a light derivative (2) for converging and / or diffusing light is formed on an upper portion where LEDs (1) are arranged in an array. 2. The LED lighting structure according to claim 1, wherein the light derivative (2) has a waveform or a tooth shape. 3. The LED lighting structure according to claim 2, wherein the light derivative (2) has a half mirror waveform or tooth shape. 4. The LED lighting structure according to claim 1, wherein said light derivative (2) has a shape having a light converging portion and a light diffusing portion. 5. The optical derivative (2) is a cylindrical lens (4) having a lens (3) on the LED (1) side or the subject (5) side with a light diffusing portion. Item 5. An LED lighting structure according to Item 4. 6. A cylindrical lens (4) having a light diffusion part having a roughened surface on the LED (1) side or on the object (5) side as the light derivative (2). 4. The LED lighting structure according to 4. 7. The optical derivative (2) is a cylindrical lens (4) having a milky white filter portion (6) on the LED (1) side or on the subject (5) side. LED lighting structure as described. 8. The LED lighting structure according to claim 7, wherein said filter section (6) is replaceable for color correction on an LED (1) side or a subject (5) side.