JP2013228590A - Light guide plate for photographing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable anybody other than a professional photographer to photograph a subject finely.SOLUTION: A light guide plate for photographing is configured in such a manner that: a light-reflecting reflection plate 4 is superimposed on one side 3 of a flat plate-like transparent resin board 2 in which a substantially L-shaped curved portion 11 is formed in a substantially central part in the longitudinal direction thereof, and a light-diffusing diffusion plate 6 is superimposed on the other side 5 of the resin board, the plates 4, 6 sandwiching the transparent resin board 2 therebetween; dot printing 15 formed such that the size of dots becomes larger as they approach the central part from both ends in the longitudinal direction of the transparent resin board is applied to the one side 3 which is the rear face of the transparent resin board; frames 8, 9 incorporating a plurality of LEDs 7 along edge faces in a width direction of the transparent resin board are arranged at both ends 12, 13 in the longitudinal direction of the transparent resin board; and outgoing light from the LEDs of both ends are collected together in the curved portion 11 of the transparent resin board 2.

Description

  The present invention relates to a light guide plate for taking a picture, and more specifically, when taking a photograph of a catalog of a product for sale or a photograph for magazine publication, the shadow of a subject as a subject is not reflected in the photograph taken by illumination. The present invention relates to a light guide plate capable of taking clear pictures with uniform brightness.

  Conventionally, when taking a catalog photo of a product for sale or a photo for publication in a magazine, ask a professional photographer to shoot, or prepare necessary equipment (for example, a strobe and a stand for fixing it). However, at that time, a plain or patterned curtain or back paper is arranged around the subject's installation surface and its surroundings, and a plurality of frames for mounting lighting fixtures are combined to attach a strobe or lighting fixture there. It is normal to shoot by adjusting the irradiation direction and illuminance so that the shadow of the subject does not appear.

  In recent years, a signboard or sign plate (light-emitting plate) using a liquid crystal (LCD) or LED (light-emitting diode) is arranged behind or to the side of the subject to irradiate the subject and take a picture. Yes.

JP 2006-154117 A (FIG. 1) JP 2010-256579 A (FIG. 5) Japanese Patent Laying-Open No. 2005-352400 (FIG. 2)

  In the case of the conventional photography method described above, a large amount of setup time is usually spent for carrying in equipment for preparing for photography, arranging lighting fixtures, adjusting illuminance, and the like. In addition, a film camera is usually used as a camera for photographing, but using a digital camera sold in recent years, photographing using the auto function of the camera is also performed. In this case, there is a slight difference in contrast and hue from the photo taken with the film camera depending on the reflection of the subject and the degree of illumination, so a considerable technique can be used to produce a fine and beautiful photo image similar to the film camera. There is a problem that it takes.

  This is because, in the case of a digital camera, the subject viewed by the camera itself is automatically (automatically) automatically adjusted by the internal function to optimize the camera according to the camera characteristics. This is partly because the camera itself cannot be finely adjusted manually, such as a shooting technique based on the experience and feeling of the person (such as subject depth and exposure adjustment in accordance with film sensitivity).

  In particular, in the case of a subject whose hue changes slightly depending on the degree of reflection of light, such as bottles, transparent glass products, colored plastic furniture and accessories, the reflection or subject of illumination is not limited even if indirect illumination is used. In order to prevent the shadows of the subject from appearing, the photographer himself / herself needs advanced photographing techniques such as illumination direction and illumination adjustment.

  Furthermore, when using the above-mentioned liquid crystal signboards and sign plates, etc., there are advantages of power saving, light weight and thinness, but on the other hand, the liquid crystal composition is used to modulate and display light, so that it is flat and There is a problem that flexibility is difficult and expensive. Also, when shooting, it is necessary to arrange a plurality of light emitting plates below and behind the subject, the luminance of the light emitting plate itself is not uniform, and the boundary line with the combination part becomes a light shading line. There is also a problem of being projected in a shape.

  Therefore, the present invention uses a light-weight and inexpensive single-purpose device using a power-saving light-emitting diode (LED), so that even non-professionals can take advantage of the auto-function of a digital camera and be as fine and beautiful as a photo by a film camera. An object of the present invention is to provide a light guide plate for photographing that can easily photograph a photograph.

  In order to solve the above problem, the present invention has a flat transparent resin plate 2 in which a substantially L-shaped curved portion 11 is formed at a substantially central portion in the longitudinal direction and one side 3 sandwiching the transparent resin plate. A reflecting plate 4 that reflects light is overlapped, and a diffusion plate 6 that diffuses light is overlapped on the other side 5, and one side 3 that is the back surface of the transparent resin plate is formed on both sides of the longitudinal direction of the curved portion. A frame in which dot printing 15 is formed so that the dot size increases as it approaches the center, and a plurality of LEDs 7 are built in the longitudinal ends 12 and 13 along the widthwise end faces of the transparent resin plate. 8 and 9 are arranged so that light emitted from both the LEDs is condensed on the curved portion 11 of the transparent resin plate 2 (Claim 1).

  The dot pitch in the longitudinal direction of the dot printing may be formed so as to gradually increase from both ends in the longitudinal direction of the transparent resin plate toward the center of the curved portion (Claim 2).

  In the dot arrangement, assuming that the diameter of the dot is D and the pitch of the dot center is P, the D / P is sequentially in the range of approximately 0.2 to 1.0 as the distance from the LED light source to the center of the curved portion is approached. It is good to set so that it may change (Claim 3).

  Furthermore, the dot printing can be formed such that both the dot pitch and the dot size in the longitudinal direction gradually increase from both ends in the longitudinal direction of the transparent resin plate toward the center of the curved portion. 4).

  Further, the dot density in the longitudinal direction of dot printing provided on the back surface of the transparent resin plate is low in density near the light source of the LED provided on both end surfaces of the transparent resin plate, and approaches the center of the curved portion. It is good to set to high density (Claim 5).

  Furthermore, the dot area ratio (dot density) per unit area in the longitudinal direction of the dot printing is set so as to sequentially change in a range of approximately 3% in the vicinity of the LED light source and approximately 75% as the center of the curved portion is approached. (Claim 6).

  Further, the curved portion of the transparent resin plate may be formed with a flat portion having a length larger than the radius of curvature of the curved portion between both ends in the longitudinal direction across the curved portion. ).

  Moreover, it is preferable to provide a plurality of heat-dissipating protrusions along the length direction of the partition wall on the LED rear surface of the frame disposed at the end of the transparent resin plate.

  According to the present invention, light irregularly emitted from the surface of the light guide plate emits light uniformly on the surface without uneven brightness. Therefore, when a subject to be photographed is placed on the light guide plate, the periphery of the subject is uniformly and evenly irradiated by light that diffuses from the front, rear, left, and right of the light guide plate. Will not be reflected. Therefore, even a non-professional person who has little shooting experience can easily take a clear and vivid picture using the auto function of the digital camera.

  In addition, because the back of the subject is formed at infinity at the curved portion of the light guide plate, there is no shading of light that occurs at the boundary of the combined portions of the light emitting plates as in the prior art, and the surrounding area has a uniform background. As a light guide plate that is projected, power-saving, lightweight, and easy to move and install, its use effect is great.

It is a general view of this invention light-guide plate main body. It is an end view when the light guide plate main body is cut in the vertical direction. It is explanatory drawing of the dot of a dot printing part. It is an expanded sectional view of an upper frame. It is an expanded sectional view of a lower frame. It is explanatory drawing which has arrange | positioned the to-be-photographed object on the light-guide plate main body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5. The present invention is not limited to the embodiments described below, and various modifications can be made within the scope of the gist of the present invention.

  FIG. 1 is an overall view of a light guide plate main body 1 according to the present invention. FIG. 2 is an end view of the light guide plate cut in the vertical direction. The light guide plate main body is substantially rectangular and has a substantially central portion in the longitudinal direction. Curved in an L-shape, transparent and flat transparent resin plate 2 and the transparent resin plate sandwiched between the reflector 4 on one side 3 and the diffuser plate 6 on the other side 5 It is configured to overlap.

  Further, an upper frame 8 for reinforcing and protecting an LED (light emitting diode) 7 as a light source and a lower frame 9 are disposed on both end faces in the longitudinal direction, and the transparent resin plate 2 and the reflecting plate 4 are diffused. The end of the plate 6 is clamped and fixed. Similarly, side frames 10 (FIG. 1) having the same shape are arranged on both side end surfaces of the light guide plate main body, and are sandwiched and fixed so as to surround the periphery of the light guide plate main body 1 by the respective frames as a whole.

  In addition, although the white color of the LED is normally used as the LED color, several kinds of light emission colors can be used properly or mixed depending on the photographing purpose of the subject. In that case, adjustment is made with a dot pattern to be described later so as not to cause color unevenness in each emission color. The side frame 10 is provided to reinforce and protect the side surface of the light guide plate main body. However, when the width of the light guide plate main body is increased in accordance with the size of the subject, the light emitted from the diffuser plate 6 is emitted. In the present embodiment, the LED will not be built in, but will be described below because the LED can be built in the same way as the upper frame 8 and the lower frame 9.

  The transparent resin plate 2 is made of a transparent and plate-like acrylic resin (Polymethyl Methacrylate (PMMA)) having a thickness of about 5 to 15 millimeters, and scatters light on one side 3 corresponding to the back surface thereof. Dot printing 15 is applied. The transparent resin plate 2 is not limited to the above-described materials, and for example, a transparent resin such as transparent polycarbonate or polystyrene polypropylene is used which is highly transparent and excellent in weather resistance and has a good balance of thermal characteristics, mechanical strength, moldability, and the like. Also good.

  The light guide plate body 1 is formed with a substantially L-shaped curved portion 11 at a substantially central portion thereof, and a flat portion 14 is formed between the both end surfaces 12 and 13 from the curved portion. The curved portion 11 is formed by forming the back surface of the subject 30 in a gentle curved shape so that the surface brightness of the light guide plate body serving as the background is uniformly maintained. This is also related to the dot size, dot density, and the like.

  That is, when the radius of curvature of the curved portion is small, the emitted light from both the LEDs 7 arranged at both ends of the light guide plate body 1 is condensed on the curved portion, and so-called hot spots where the brightness in the vicinity thereof is partially increased. And the brightness of the entire surface becomes non-uniform and reflected in the photograph. In addition, an infinite distance is not formed in the background portion of the subject, and the boundary between the flat portion and the curved portion is projected linearly. There is a problem. Therefore, as a result of trial and error, the inventors of the present invention should make the radius of curvature of the curved portion at least in the range of about 5% to 20% of the entire length of the light guide plate body 1 and preferably about 15%. I found out.

  In this case, the lengths of the flat portions 14 formed on both the curved portions 11 may not be equal depending on the shape and size of the subject 30, but when the subject 30 is disposed on the light guide plate body 1. It is preferable to set the back surface of the subject at an appropriate interval so as not to be affected by the luminance and to have a length larger than the radius of curvature of the curved portion.

  Further, the dot printing 15 applied to the back surface of the transparent resin plate 2 is usually printed when the transparent resin plate 2 is in a flat state, and the printing is performed on the surface of the ink having resin components having different refractive indexes. In addition, for example, screen printing with a paint containing silica, titanium oxide or the like is performed, and after the printing is completed, the light guide plate body 1 is formed by bending the transparent resin plate. It may be formed into a fine concavo-convex shape by thermal transfer or UV curable resin, or a prism pattern in units of microns is formed on the surface of the mold, and the transparent resin plate itself is manufactured in one step by transferring it. Good.

  FIG. 3 shows an exaggerated example of the dot arrangement of the dot printing unit 15, in which substantially circular dots 16 are arranged in a staggered pattern at regular intervals on the back surface of the transparent resin plate 1 with a predetermined pitch interval P. ing. In the present embodiment, when the dot size (dot diameter) is D and the dot pitch (interval between dot centers) in the longitudinal direction of the light guide plate is P, the dot size D is both ends of the transparent resin plate 2 in the longitudinal direction. In the vicinity of the LED 7 that is a light source arranged in the above, the dot size D is reduced, and the dot size D is gradually increased toward the center of the curved portion 11 and is maximized at the center of the curved portion.

  The reason for this is that light incident from the end faces 12 and 13 of the transparent resin plate 2 is reflected by the reflecting plate 4 provided on the back side of the transparent resin plate 2 through the dot printing part, and is transmitted and refracted after the direction change. After being incident on the diffusion plate 6 on the other side (front side) 5, the light is emitted from the outermost surface of the diffused plate 6. At this time, the light is emitted from both end surfaces of the transparent resin plate 2 as it approaches the vicinity of the central portion of the curved portion 11. In order to prevent the light from the LEDs from condensing in the vicinity of the curved portion and generating hot spots with high brightness and unevenness in a relatively ring, circle, or ellipse shape, this makes it closer to the light source. The amount of reflected light at a distant place is averaged and uniform, and surface emission occurs.

  In addition, dimensional relations such as the dot size and the dot pitch in the present embodiment will be described. The curvature radius R of the curved portion is 200 millimeters with respect to the total length of the transparent resin plate 1, and the dot pitch P in the longitudinal direction thereof is Each dot 16 is arranged in a zigzag pattern on a 3.9 mm grid-like center line, and each dot size D is approximately 1 mm in diameter in the vicinity of the LED light source, and a maximum diameter of 3.3 in the center of the curved portion 11. It is set to millimeters, and the dot size therebetween gradually changes in proportion to the distance.

  More specifically, this mutual relationship between dimensions is a result of trial and error by the present inventors. For example, when the dot diameter is D and the dot center pitch is P, D in the vicinity of the LED light source. It is preferable to set so that / P is approximately 0.2, D / P is approximately in the range of 1.0 at the center of the curved portion, and sequentially changes in the range of 0.25 to 0.85 as a result of the trial. In other words, the ratio of the occupied area (light transmission area) of dots per unit area on the surface of the transparent resin plate 2 (hereinafter referred to as dot density) is approximately 3% in the vicinity of the LED light source, and approximately 75% as it approaches the center of the curved portion. It is preferable that the range is good, and it is preferable to set it so that it changes sequentially in the range of 4.5% to 50% as a result of the trial. Applicable.

  Regarding the arrangement of the dots 16, for example, the dot size D is set in the same manner as described above, and only the dot pitch P is changed to adjust the interval, that is, the vicinity of both ends in the longitudinal direction of the transparent resin plate 2. Then, even if the dot pitch P is decreased and the dot pitch is gradually increased as the distance from the center of the curved portion 11 increases, the dot density per unit area decreases to a low density near the both ends and also approaches the center of the curved portion 11. Accordingly, the same effect is obtained because the density gradually changes.

  In addition, the dot density is not limited to the shape of the dot, i.e., a circle, but can be applied to an ellipse, a triangle, a square, a rectangle, and other shapes. Which of these changes is used as a reference may be appropriately selected in accordance with the shape and size of the subject 30, the amount of light on the surface of the light guide plate, and the like.

  Further, when changing the size of the light guide plate, the smaller the radius of curvature R of the curved portion 11, the smaller the dot size D of the curved portion, and the larger the radius of curvature of the curved portion, the larger the dot size D. These settings are suitably set corresponding to the size of the light guide plate body 1 and the radius of curvature of the bending portion 11.

  On the other hand, the reflecting plate 4 described above may be a white resin sheet having a thickness of approximately 0.2 mm and a high reflectance, or a white pigment or the like may be applied to the resin sheet, and the diffusion plate 6 may be approximately 1.5 mm. A transparent substrate having a thickness of 10 mm is provided with light diffusion performance, and a thermoplastic resin such as methacrylic resin, polycarbonate resin, polystyrene resin, polyolefin resin or the like is used as the material. For example, a light diffusing agent is dispersed. Alternatively, a transparent resin layer may be used.

  In addition, although the transparent resin board 2 demonstrated using the transparent acrylic resin board in a present Example, the diffusing agent is uniformly disperse | distributed previously in the raw material of transparent resin, for example, and such a raw material is used. If an acrylic resin plate manufactured by cast molding, extrusion molding, injection molding, press molding or the like is used, the diffusion plate itself can be dispensed with and the number of parts can be reduced.

  4 and 5 show cross-sectional shapes of an upper frame 8 and a lower frame 9 made of a light and relatively high thermal conductivity material such as aluminum or a reinforced resin composite material. A plurality of LEDs 7 are arranged along the width direction of the plurality of LEDs 7 at appropriate intervals (approximately 15 mm intervals in the present embodiment) while facing the end surfaces along the width direction of the transparent resin plate 2. The reflection plate 4 is sandwiched and fixed on one side 3 and the end portion of the diffusion plate 6 is sandwiched on the other side 5.

  On the other hand, a plurality of projections 21 serving as heat radiating fins project along the length direction of the frame frame on the outer side of the partition wall 20 behind the LED 7 so as to radiate heat received from the LEDs to the outside. The shape of the protrusion is not particularly limited as long as it can maintain the strength of the frame and efficient heat dissipation.

  Further, the cross-sectional structure of the side frames 10 arranged on both side end surfaces of the light guide plate body 1 is the same as that of the upper frame and the lower frame, and when the light guide plate itself is used for relatively small objects, the LED It does not need to be built-in, and simply functions as a reinforcement and protection for the side surface of the light guide plate main body 1. However, when the subject 30 is relatively large, the width of the light guide plate main body 1 needs to be increased in accordance with the size of the subject. In this case, it is more effective to incorporate LEDs in the same manner as the upper frame and the lower frame from the viewpoint of averaging the light emitted from the diffusion plate 6. In addition, it is better to change the dot size D and the dot pitch P in the width direction.

  Reference numeral 25 denotes a power cord, and 26 denotes a dimming controller for adjusting the illuminance of the LED. The light guide plate receives a signal from a remote control device (not shown) and shoots the illuminance emitted from the LED 7 according to the shape of the subject or the state of transmitted light The surface brightness of the main body 1 is adjusted. Reference numeral 27 denotes a connection plug to a power outlet.

  Next, the subject photographing procedure will be described with reference to FIG. First, the light guide plate body 1 of the present invention is placed and fixed on a fixed base (not shown) prepared for photographing, and a subject 30 is placed on the flat portion 14 of the light guide plate body and connected to a power source (not shown). When the LED 7 built in each of the upper frame 8 and the lower frame 9 is energized via the connection plug 27 and the dimming controller 26, the LED emits light, and the emitted light is incident from the end faces 12 and 13 of the transparent resin plate 2 facing each other. In the process of reaching the central curved portion 11 along the surface of the rear light guide plate main body 1, the light enters the reflector 4 through the dot printing unit 15, repeats direction change and refraction, and enters the diffuser 6 after entering the diffuser 6. Light scatters from the outermost surface and radiates outside.

  At the same time, the light emitted from the outermost surface of the light guide plate body also emits light with uniform brightness throughout the front, back, left, and lower sides of the subject 30 disposed on the light guide plate body 1, and the subject is evenly distributed. Irradiate. At this time, the shadow is canceled out by the ambient light by the light irradiated from below the subject, and in the photographed image, only the subject is projected.

  This is especially effective when taking pictures of objects whose color changes slightly due to light reflection, such as colored bottles, transparent glass, plastic furniture and accessories, etc., using the auto function of the digital camera. Since the surrounding light is uniformly illuminated with uniform light and the light emission brightness of the LED can be freely adjusted by the dimming controller 26, it is possible to obtain a clear and vivid photograph with light emission at an appropriate brightness and without the occurrence of shade of the article. Become. Therefore, it is possible to easily shoot even a non-professional person with little experience, and the use range is great as a light-weight, power-saving and simple photographing instrument by adopting the LED as the light source of the light guide plate body 1 itself. is there.

DESCRIPTION OF SYMBOLS 1 Light-guide plate main body 2 Transparent resin plate 3 One side 4 Reflecting plate 5 Other side 6 Diffusion plate 7 LED
8 Upper frame 9 Lower frame 10 Side frame 11 Curved portion 12 End surface 13 End surface 14 Flat portion 15 Dot printing portion 16 Dot 20 Bulkhead 21 Protrusion 25 Power cord 26 Dimming controller

Claims (8)

  A flat plate-shaped transparent resin plate having a substantially L-shaped curved portion at the center in the longitudinal direction, a reflecting plate that reflects light on one side of the transparent resin plate, and light diffusion on the other side In addition to overlapping the diffuser plates to be applied, dot printing is performed on one side which is the back surface of the transparent resin plate so that the dot size increases from both ends in the longitudinal direction toward the center of the curved portion. A frame containing a plurality of LEDs along the end face in the width direction is disposed at both ends in the longitudinal direction of the transparent resin plate, and light emitted from both the LEDs is collected at the curved portion of the transparent resin plate. A light guide plate for photography, wherein the light guide plate is configured to emit light.   2. The photographic print according to claim 1, wherein the dot pitch in the longitudinal direction of the dot printing is formed so as to gradually increase from both ends in the longitudinal direction of the transparent resin plate toward the center of the curved portion. Light guide plate.   In the dot arrangement, assuming that the dot diameter is D and the dot center pitch is P, D / P gradually changes in the range of approximately 0.2 to 1.0 as it approaches the center of the curved portion from the vicinity of the LED light source. The light guide plate for photography according to claim 1, wherein the light guide plate is set as follows.   The dot printing is formed such that both the dot pitch and the dot size in the longitudinal direction gradually increase from both ends in the longitudinal direction of the transparent resin plate toward the center of the curved portion. The light guide plate for photography as described.   The dot density in the longitudinal direction of the dot printing provided on the back surface of the transparent resin plate is low in density near the light source of the LED provided on both end surfaces of the transparent resin plate, and becomes high as it approaches the center of the curved portion. The light guide plate for photography according to claim 1, wherein   The ratio (dot density) of the dot area per unit area in the longitudinal direction of the dot printing is set so as to sequentially change in a range of approximately 3% in the vicinity of the LED light source and approximately 75% as it approaches the center of the curved portion. The light guide plate for photography according to claim 5.   The curved portion of the transparent resin plate is characterized in that flat portions having a length larger than the curvature radius of the curved portion are formed between both ends in the longitudinal direction across the curved portion. The light guide plate for photography according to claim 1. 2. The photographic projection according to claim 1, wherein a plurality of heat radiation protrusions are provided along a length direction of the partition wall on the rear surface of the LED of the frame disposed at the end of the transparent resin plate. Light guide plate.

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