JP2006258986A - Light emission device and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emission device improved in the selectivity of luminous intensity and advantageous in micro fabrication, and also to provide an imaging apparatus. <P>SOLUTION: The light emission device is provided with a light emission element 13, a lens 15 made of plastic resin on which the light of the light emission element is made incident, and a light distribution angle variable mechanism 20 which changes light distribution angle of the light emitted via the lens by changing a curvature of the lens. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting device and an imaging device, and is applied to, for example, auxiliary light, a mobile phone with a camera, and the like.

  Conventionally, light emitting diodes (LEDs) have been applied to various fields such as panel lighting for automobile meters, illumination, auxiliary light for mobile phones with cameras, and key lighting. Among them, mobile phones are equipped not only with an information transmission function but also with a camera for taking still images and videos. The original camera phone had no auxiliary light, a so-called flash. However, with the advent of white LEDs in recent years and the enhancement of their brightness, small and bright LED auxiliary lights and LED flashes have been used for camera-equipped mobile phones (see, for example, Patent Document 1).

  Here, generally, when the subject is far away, it is necessary to reduce the light distribution angle of the LED auxiliary light and the LED flash and increase the luminous intensity of the subject. This is because the light is focused on a distant subject to brighten the vicinity of the subject. On the other hand, when the subject is close, it is necessary to increase the light distribution angle of the LED auxiliary light or the like to reduce the luminous intensity of the subject. This is because the light is scattered over a wider area including the subject to uniformly brighten the wide area.

  Therefore, by mounting two types of lenses, a near-illumination lens and a far-distance illumination lens having different curvatures in the light emission direction of the LED auxiliary light and the like, and selecting one of the two lenses, LED auxiliary light or the like A light emitting device has been proposed in which the light distribution angle is selected and the luminous intensity is switched between the far and near scenes.

  However, in the configuration as described above, only two luminous intensity angles can be selected, so only two luminous intensity can be selected. For example, a desired luminous intensity cannot be selected for an object at an intermediate distance corresponding to the two lenses. For this reason, there is a problem that the light intensity selectivity according to the distance to the subject is low.

  In addition, since it is necessary to mount two types of switchable lenses, there is a problem that the exclusive area for the lenses increases, which is disadvantageous for miniaturization.

  Furthermore, if the photographer forgets to switch the lens, the light intensity is insufficient for a distant subject and the image becomes dark, and the light intensity is excessive for a close object, so-called whitening (halation) occurs.

  In addition, the same problem as described above also occurs in the imaging apparatus including the light emitting device.

As described above, the conventional light emitting device and imaging device have a disadvantage in that the selectivity of light intensity is low and miniaturization is disadvantageous.
JP 2004-140883 A Specification

  In view of the circumstances as described above, the present invention provides a light emitting device and an imaging device that can improve the selectivity of luminous intensity and are advantageous for miniaturization.

  According to one aspect of the present invention, a light emitting element, a lens formed of a plastic resin, the light incident on the light emitting element, and the light emitted through the lens by changing the curvature of the lens. It is possible to provide a light emitting device including a variable light distribution angle mechanism that changes the light distribution angle of the light distribution angle.

  According to one aspect of the present invention, a light emitting element provided in a surface of a semiconductor substrate, a lens formed of a plastic resin, and the light from the light emitting element is incident thereon, and attached to an end of the lens, A lens fixing plate that moves in the direction of the surface of the semiconductor substrate, and a drive that generates / extinguishes electrostatic force that is electrically connected to the lens fixing plate on the semiconductor substrate and works to repel each other. A light-emitting device including a variable light distribution angle mechanism including a cell can be provided.

  According to one aspect of the present invention, a light emitting element provided in a surface of a semiconductor substrate, a lens formed of a plastic resin and receiving light of the light emitting element, a motor, and electrically connected to the motor And a control device configured to control the number of rotations of the motor, a feed shaft that is rotated by the motor and rotates according to a control signal of the control device, and is connected to the feed shaft through the end of the lens And a light distribution device including a variable light distribution angle mechanism including a feed screw that moves along a feed axis direction and pulls or compresses an end portion of the lens by a linear motion according to the rotational motion of the feed shaft. Can be provided.

  According to one aspect of the present invention, a light emitting element, a lens formed of a plastic resin, on which the light of the light emitting element is incident, and the light emitted through the lens by changing the curvature of the lens. A light emitting device including a light distribution angle variable mechanism that changes a light distribution angle, and a photographing device including a zoom mechanism, and the light distribution angle variable mechanism includes the lens when the photographing device zooms in. The curvature of the lens is changed so that the light distribution angle of light emitted from the lens becomes small, and when the photographing apparatus zooms out, the lens has a large light distribution angle of light emitted from the lens. An imaging device that works in conjunction with the zoom mechanism can be provided so as to change the curvature of the zoom lens.

  According to the present invention, it is possible to improve a light intensity selectivity and obtain a light emitting device and an imaging device advantageous for miniaturization.

  Embodiments of the present invention will be described below with reference to the drawings. In this description, common parts are denoted by common reference symbols throughout the drawings.

[First Embodiment]
A light emitting device according to a first embodiment of the present invention will be described with reference to FIGS. This embodiment is an example in which the light emitting device is realized by so-called MEMS (micro electro mechanical systems) manufactured by applying semiconductor processing technology. FIG. 1 is a plan view showing the light emitting device according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG.

  As shown in the drawing, an LED (light emitting diode) element 13 is provided at the bottom of a groove 12 formed in a mortar shape in a silicon (Si) substrate 11. A transparent resin 14 mixed with phosphors is poured into the groove 12 to seal the LED element 13. For example, when the LED element 13 emits blue light, the phosphor is mixed with a yellow phosphor, and when the LED element 13 emits near ultraviolet light, three primary color phosphors are mixed.

  A lens 15 is provided in the light emitting direction of the LED element 13. The lens 15 is made of, for example, a plastic resin containing silicon or the like. Therefore, by pulling or compressing the end portion 16 of the lens 15, the surface thereof can be made flat or bent, and the curvature of the lens 15 can be changed.

  In order to change the light distribution angle of the light emitted from the lens 15 by pulling or compressing the end 16 of the lens, a variable light distribution angle mechanism 20 is provided.

  The variable light distribution angle mechanism 20 includes a lens fixing plate 21 provided with the upper surface attached to the lower surface of the end portion 16 of the lens and suspended from the substrate 11, and the lens fixing plate 21 provided on the substrate 11. Drive cells 25 for generating / extinguishing electrostatic forces acting so as to repel each other.

  Next, the variable light distribution angle mechanism 20 will be described in detail with reference to FIG. FIG. 3 is a perspective view showing the variable light distribution angle mechanism 20. In this drawing, illustration of the lens 15 to be provided on the upper surface of the lens fixing plate 21 is omitted.

  As shown in the figure, both side surfaces of the lens fixing plate 21 in the gate length direction are supported by arms 22 (illustration of the front arm is omitted). The arm 22 is connected to the support bases 23-1, 23-2. One support base 23-2 is provided on the surface of the floating electrode 28, and the other support base 23-1 is provided on the front surface of the substrate 11 (not shown). The fixing plate 21 is floating from the surface of the substrate 11.

  The lens fixing plate 21, the arm 22, and the support bases 23-1, 23-2 are made of, for example, polysilicon.

  The drive cell 25 includes a gate insulating film 27, a floating electrode 28, a source / drain 29, a control electrode 30, and an inter-gate insulating film 31.

  The gate insulating film 27 is provided on the surface of the substrate 11. The floating electrode 28 is provided on the gate insulating film 27. The control electrode 30 is provided on the floating electrode 28 so as to sandwich the inter-gate insulating film 31 together with the floating electrode 28. A source / drain 29 is provided on the back side and the near side in the drawing so that the floating electrode 28 is sandwiched along the gate length direction (the source / drain 29 on the near side is shown in the figure). Not shown). One end of the floating electrode 28 extends in the gate width direction, and a support base 23-2 is provided on the upper surface thereof. The floating electrode 28 and the lens fixing plate 21 are electrically connected.

  Furthermore, electrostatic forces that repel each other act between one side surface of the floating electrode 28 and one side surface of the lens fixing plate 21 in the gate width direction. With this electrostatic force, the lens fixing plate 21 moves away from the floating electrode 28 in the direction along the surface of the substrate 11, and the curved lens 15 can be made flat.

The gate insulating film 27 and the inter-gate insulating film 31 are formed of, for example, a silicon oxide film (SiO ₂ ) or the like, and are formed of the floating electrode 28 and the control electrode 30 such as polysilicon. The source / drain 29 is formed, for example, by injecting an impurity having a conductivity type different from that of the semiconductor substrate 11 such as boron (B) into the substrate 11 by thermal implantation and the like.

<Operation>
Next, the operation of the light emitting device according to this embodiment will be described with reference to FIGS. 4 and 6 are plan views illustrating the light distribution angle variable mechanism 20 for explaining the operation according to this embodiment. 5 and 7 are sectional views for explaining the operation according to this embodiment and showing the state of light emission of the light emitting device.

  First, the operation when the subject A1 is close to the lens 15 will be described. In this case, it is necessary to increase the light distribution angle of the light emitted from the lens 15 to reduce the luminous intensity, diffuse the light over a wide range, and uniformly brighten the wide range. This is done by injecting electrons from the driving cell 25 into the lens fixing plate 21 and generating an electrostatic force 35 between the floating electrode 28 and the lens fixing plate 21.

  First, either one of the source / drain 29 is grounded. Subsequently, a high potential is applied to the other of the control electrode 30 and the source / drain 29. Then, so-called hot electrons (hot electrons) are generated in the channel region, the hot electrons tunnel through the gate insulating film 28, and electrons are injected into the floating electrode 28.

  Here, since the floating electrode 28 and the lens fixing plate 21 are electrically connected to each other, as shown in FIG. A repulsive electrostatic force is generated between the floating electrode 28 and the lens fixing plate 21 so that the lens fixing plate 21 is separated from the floating electrode 28 from the original position 36 along the gate width direction. It moves along the surface of the substrate 11. Thereafter, the lens fixing plate 21 stops at a position where the restoring force for returning to the original position 36 and the electrostatic force balance.

  Therefore, the lens end 16 provided on the upper surface of the lens fixing plate 21 is pulled outward, and the lens 15 becomes flat. And the curvature of the lens 15 changes and the light 41 with a large light distribution angle is radiate | emitted. As a result, the luminous flux per cross-sectional area S1 including the subject A1 is reduced, the luminous intensity is reduced, the light is diffused over a wide range, and the wide range is uniformly brightened.

  Thereafter, even if a high potential is no longer applied to the other of the control electrode 30 and the source / drain 29, the electrons injected into the floating electrode 28 are confined in the floating electrode 28 by the gate insulating film 27 and the inter-gate insulating film 31. It is done. Therefore, the electrostatic force is maintained, the lens fixing plate 21 is stationary at this position, and light 41 having a desired large light distribution angle continues to be emitted.

  Next, an operation when the subject A1 is separated from the lens 15 will be described. In this case, it is necessary to reduce the light distribution angle of the light emitted from the lens 15 to increase the luminous intensity and to collect the light near the subject. This is done by extracting the electrons injected into the floating electrode 28 to the source / drain 29 to return the floating electrode 28 to neutral, thereby eliminating the electrostatic force.

  First, one of the source / drain 29 is opened. Subsequently, the control electrode 30 and the substrate 11 are grounded. Subsequently, when a high potential is applied to one of the source / drain 29, electrons in the floating electrode 28 are pulled out to one of the open source / drain 29, and the floating electrode 28 returns to neutral. Therefore, the charge distribution disappears inside the floating electrode 28 and the lens fixing plate 21, the electrostatic force generated between the control electrode 28 and the lens fixing plate 21 disappears, and the lens fixing plate 21 is restored. It moves to the original position 36 according to the force.

  Therefore, the lens 15 bends as originally according to the lens end portion 16 provided on the upper surface of the lens fixing plate 21. Then, the curvature of the lens 15 changes, and light 45 having a small light distribution angle is emitted. As a result, the luminous flux per cross-sectional area S2 including the subject A1 is increased, the luminous intensity is increased, and the light is condensed near the subject.

  In the above operation, for example, by selecting the curvature of the lens 15 by reducing the number of electrons injected into the floating electrode 28 by, for example, selecting to lower the potential applied to the control electrode 30 when injecting electrons, It is also possible to emit light having a light distribution angle that is about the middle of the light distribution angles of the lights 41 and 45. In the above case, for example, it is possible to select a low potential to be applied to one of the source / drain 29 when extracting electrons.

  The light distribution angle variable mechanism 20, the LED element 13, and the like can be formed by applying a semiconductor processing technique.

  According to the light emitting device according to this embodiment, the following effects (1) to (3) can be obtained.

(1) Since an appropriate light distribution angle corresponding to the distance to the subject can be selected, the light intensity selectivity can be improved.

  As described above, the light distribution angle changing mechanism 20 changes the curvature of the lens 15 formed of a plastic resin such as silicon, changes the light distribution angle of the light collected by the lens, and selects the light intensity. Can do. The light intensity is selected by injecting or extracting electrons from the floating electrode 28 so that the lens fixing plate 21 attached to the lens 15 is separated from the original position or returned to the original position.

  Therefore, for example, by selecting a voltage value to be applied to the source / drain 29 and controlling the amount of electrons injected or extracted, for example, light having a light distribution angle that is about the middle of the light distribution angles of the light 41 and 45 Can also be emitted. As a result, it is advantageous in that an appropriate light distribution angle corresponding to the distance of the subject can be selected, and the selectivity of luminous intensity can be improved.

(2) It is advantageous for miniaturization.

  As described above, the light emitting device according to this embodiment can change the light distribution angle by changing the curvature of the lens 15 itself. Therefore, for example, there is no need to provide a plurality of lenses having different curvatures. As a result, it is advantageous in that an increase in exclusive area due to an increase in the number of lenses can be prevented and miniaturization can be achieved.

  The direction in which the lens fixing plate 21 moves is not in the direction perpendicular to the surface of the substrate 11 but in the direction along the surface of the substrate 11. Therefore, an increase in the area accompanying the movement of the lens fixing plate 21 is prevented, which is advantageous for miniaturization.

  Further, the variable light distribution angle mechanism 20 can be formed by applying a semiconductor processing technique. Therefore, for example, when the drive cell 25 is formed by using a photolithography method, it is possible to make it fine by selecting a wavelength of a laser for exposing the applied photoresist. In addition, other configurations such as the LED element 13 can be formed simultaneously with the drive cell 25 in the element region of the silicon substrate 11, which is advantageous for miniaturization.

(3) It is advantageous for reducing power consumption.

  The electrons injected into the floating electrode 28 are insulated by the gate insulating film 27 and the inter-gate insulating film 31 and confined in the floating electrode 28. Even when a high potential is no longer applied to the control electrode 30 and the source / drain 29, the electrostatic force is maintained, the lens fixing plate 21 remains stationary, and light 41 having a large desired light distribution angle continues to be emitted. .

  This eliminates the need for power for maintaining the light distribution angle, which is advantageous in that power consumption can be reduced.

[Second Embodiment]
Next, a light emitting device according to a second embodiment of the present invention will be described with reference to FIG. This embodiment is an example in which the light distribution angle variable mechanism 20 is mechanically realized. FIG. 8 is a cross-sectional view showing the light emitting device according to this embodiment. In this description, the description overlapping with the first embodiment is omitted.

  As shown in the figure, the LED element 13 is provided on the cathode electrode 46-1 in the ceramic substrate 40, and is mounted with silver (Ag) paste, AuSn solder, or the like. Further, it is connected to the anode electrode 46-2 by a bonding wire (not shown). And it is sealed with the transparent resin 14 and the envelope 42.

  The variable light distribution angle mechanism 20 includes a control device 47, a motor 48, a feed shaft 49, and a feed screw 50 provided on the envelope 42.

  The control device 47 is electrically connected to the motor 48 and is configured to control the rotation speed of the motor 48. The motor 48 rotates the feed shaft 49 at a rotational speed according to a control signal from the control device 47. The feed screw 50 passes through the end 16 of the lens and is connected to the feed shaft 49.

  The feed screw 50 moves along the feed axis direction by a linear motion according to the rotational motion of the feed shaft 49, and pulls or compresses the end 16 of the lens. Then, the luminous intensity is selected by changing the light distribution angle of the light emitted from the lens 15.

  When pulling the end 16 of the lens, the feed shaft 49 is rotated and the feed screw 50 is moved along the feed shaft direction away from the motor 48. On the other hand, when compressing the end 16 of the lens, the feed shaft 49 is rotated in the reverse direction, and the feed screw 50 is moved along the feed shaft direction so as to approach the motor 48.

  The detailed description of the operation is substantially the same as that in the first embodiment, and will be omitted.

  As described above, according to the light emitting device according to this embodiment, the same effect as in the first embodiment can be obtained. Furthermore, as described in this embodiment, the light distribution angle variable mechanism 20 and the like can be mechanically configured as necessary.

[Embodiment (Imaging Device)]
Next, an imaging apparatus according to an embodiment of the present invention will be described with reference to FIG. This embodiment is an example of an imaging device in which the light emitting device according to the first embodiment is applied as a flash for a camera-equipped mobile phone. FIG. 9 is a cross-sectional view schematically showing the imaging apparatus according to this embodiment. In this description, the description overlapping with the first embodiment is omitted.

  As shown in the figure, a main liquid crystal screen 62 and a liquid crystal backlight LED element 63 are installed inside the main body upper part 61, and a sub liquid crystal screen 64, a liquid crystal backlight LED element 65, and a camera having a zoom mechanism are arranged on the outside. 66, a flash 51 is installed. A keypad 72 is arranged inside the main body lower portion 71, and a keypad LED element 73 is arranged inside the main body lower portion 71 so as to illuminate the keypad 72.

  The flash 51 has the same configuration as that of the light emitting device according to the first embodiment. The camera 66 includes a zoom mechanism that zooms in / out the subject to be photographed. This zoom mechanism is configured to work with the light distribution angle variable mechanism 20 of the flash 51. The zoom mechanism is composed of, for example, an electronic focus and a photographing lens.

  As described above, according to this embodiment, the same effect as in the first embodiment can be obtained. Further, in this embodiment, the zoom mechanism of the camera 66 and the flash 51 are configured to work together.

  That is, when the subject is far and the focus of the camera 66 is zoomed in, the light distribution angle of the light generated from the flash 51 can be reduced to collect the light, and the vicinity of the subject can be brightened.

  On the other hand, when the subject is close and the focus of the camera 66 is zoomed out, the light distribution angle of the light generated from the flash 51 is increased to make the light uniform, and the light intensity becomes excessive and whiteout (halation) occurs. Can be prevented.

  As described above, by interlocking with the zoom mechanism of the camera 66, it is advantageous in that the photographer can illuminate the subject with an appropriate light intensity without performing a special operation by the photographer.

  The photographer can also manually operate the camera 66 without interlocking with the zoom mechanism. For example, it is possible for the photographer to select a light distribution angle of the lens 15 by performing a predetermined operation on the keypad 72 while viewing the electronic display on the main liquid crystal screen 62 and the sub liquid crystal screen 64. In this case, it is possible to photograph with the light intensity according to the subjectivity of the photographer.

  Here, the thickness of the upper part 61 of the mobile phone main body 61 is defined from the beginning, and since it is generally thinner, the space where the flash 51 can be placed is limited. However, since the flash 51 according to this embodiment is realized by so-called MEMS, it can be arranged even in such a limited space. Therefore, it is effective for thin and small mobile phones.

  Further, since the single lens 15 attached to the upper part 61 of the mobile phone body is one, it is advantageous for miniaturization. Since only one lens 15 is required, there is an advantage in the manufacturing process that the mounting of the flash 51 can be simplified.

  Needless to say, the present invention is not limited to the camera 66 but may be a photographing device such as a video for photographing a moving image. Further, the light emitting device according to the second embodiment can also be applied as the flash 51 of the mobile phone.

  The present invention has been described above using the first and second embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. It is possible to deform. Each of the above embodiments includes various inventions, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in each embodiment, at least one of the problems described in the column of the problem to be solved by the invention can be solved, and is described in the column of the effect of the invention. In a case where at least one of the obtained effects can be obtained, a configuration in which this configuration requirement is deleted can be extracted as an invention.

1 is a plan view showing a light emitting device according to a first embodiment of the present invention. Sectional drawing along the direction of the AA 'line in FIG. The perspective view for demonstrating the light distribution variable mechanism which concerns on 1st Embodiment of this invention. The top view for demonstrating operation | movement of the light-emitting device which concerns on 1st Embodiment of this invention. Sectional drawing for demonstrating operation | movement of the light-emitting device which concerns on 1st Embodiment of this invention. The top view for demonstrating operation | movement of the light-emitting device which concerns on 1st Embodiment of this invention. Sectional drawing for demonstrating operation | movement of the light-emitting device which concerns on 1st Embodiment of this invention. Sectional drawing which shows the light-emitting device which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the imaging device which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Semiconductor substrate, 13 ... LED element, 15 ... Lens, 20 ... Light distribution angle variable mechanism, 21 ... Lens fixing plate, 22 ... Arm, 23-1, 23-2 ... Support stand, 25 ... Drive cell.

Claims (5)

A light emitting element;
A lens formed of a plastic resin and into which the light of the light emitting element is incident;
A light emitting device comprising: a light distribution angle variable mechanism that changes a light distribution angle of light emitted through the lens by changing a curvature of the lens. A light emitting device provided in the surface of the semiconductor substrate;
A lens formed of a plastic resin and into which the light of the light emitting element is incident;
A lens fixing plate attached to an end of the lens and movable in a surface direction of the semiconductor substrate; and provided on the semiconductor substrate and electrically connected to the lens fixing plate and between the lens fixing plates. A light-emitting device comprising: a variable light distribution angle mechanism including a drive cell that generates / extinguishes electrostatic force that acts to repel. The variable light distribution angle mechanism includes: a first support base provided on the drive cell; a second support base provided on the semiconductor substrate; the lens fixing plate; and the first and second support bases. An arm to be connected,
The driving cell increases the electrostatic force by injecting electrons into the lens fixing plate and moves the lens fixing plate in a direction along the substrate so as to move away from the driving cell, and pulls the end of the lens. And changing the curvature of the lens to increase the light distribution angle,
Electrons injected from the lens fixing plate are extracted to reduce electrostatic force and move the lens fixing plate in a direction along the substrate so as to approach the driving cell, compress the lens, The light-emitting device according to claim 2, wherein the light-emitting device is configured to change a curvature to reduce a light distribution angle. A light emitting element;
A lens formed of a plastic resin and into which the light of the light emitting element is incident;
A motor, a control device electrically connected to the motor and configured to control the rotation speed of the motor, a feed shaft that is rotated by the motor and rotates according to a control signal of the control device, and an end of the lens A light distribution provided with a feed screw that penetrates the portion and is connected to the feed shaft and moves along the feed shaft direction by a linear motion according to the rotational motion of the feed shaft and pulls or compresses the end of the lens A light emitting device comprising a variable angle mechanism. A light distribution element that changes a light distribution angle of light emitted through the lens by changing a curvature of the lens, a lens that is made of a plastic resin, and is incident on the light of the light emitting element. A light emitting device comprising a variable mechanism;
A photographing apparatus equipped with a zoom mechanism,
The variable light distribution angle mechanism changes the curvature of the lens so that the light distribution angle of light emitted from the lens is small when the photographing device zooms in, and the photographing device zooms out. The image pickup apparatus is interlocked with the zoom mechanism so as to change a curvature of the lens so that a light distribution angle of light emitted from the lens is increased.

Images