JP4365453B2 - Desk lighting device - Google Patents

Description

  The present invention relates to a desk lighting device using a plurality of light emitting diodes, and in particular, an improvement that can uniformly illuminate the entire illuminated area on the desk top surface with a sufficient amount of light without causing an increase in heat generation or power consumption. Regarding technology.

  As a conventional lighting fixture, various types of illumination light sources such as fluorescent lamps, incandescent bulbs, spotlights, etc. are used, but the illumination light contains ultraviolet components that induce deterioration of the irradiated object, Due to the heat generated by the illumination light source, there were many restrictions on its installation. Recently, LED light sources with low heat generation and low power consumption have attracted attention, and since white LEDs with high brightness have been provided, those using LED light sources for general lighting fixtures are increasing. . An example of this type of lighting device is disclosed in Patent Document 1, for example.

  Incidentally, one of the lighting fixtures is a desk lighting device such as a desk light. Since the desk lighting device needs to secure a work space on the desk and it is desirable to secure a space for avoiding interference above the desk surface, the lighting device body (base) is generally placed at the end of the desk surface. It is burned. Therefore, illumination light inclined from the upper part of the desk top surface to the front part is irradiated from the head provided on the base via the support column. By adopting a high-brightness LED light source in such a desk lighting device, heat generation and power consumption can be expected to be reduced as compared with a desk lighting device using a conventional fluorescent lamp or incandescent bulb.

Japanese published patent: JP 2000-021209

  However, as in the above-mentioned Patent Document 1, in an illumination device using an LED as a light source, when the illumination device is configured with a single LED or a plurality of LEDs, the illumination area of the illumination light is large when the illumination angle of the LED itself is wide. However, as the distance from the light source increases, the illuminance decreases significantly, and the performance as a lighting device cannot be satisfied. In that case, it is only necessary to increase the brightness of the light emitted from the LED itself. Therefore, by providing a reflector having a concave parabolic surface on the side (or the back side, etc.) of the LED, the light from the LED can be converted into parallel light by this reflector to increase the light flux density. The light component that has not been applied to the reflector travels forward in the optical path while diffusing. For this reason, the illuminance distribution of the entire light source can be increased by the reflector, but the illuminance distribution still exhibits a broad distribution, and a high illuminance and flat illuminance distribution illumination area necessary for illumination cannot be obtained sufficiently. In particular, in an LED illumination device, since the light emitting element itself is point light emission, it is difficult to illuminate a wide range with uniform illuminance. Moreover, in the LED illumination device, since the irradiation area is limited by the reflecting mirror, even if illumination can be performed with sufficient illuminance at the back of the desk surface, illumination can be performed with sufficient illuminance to the near side. Difficult to illuminate with uniform illuminance across the front and back of the desk. For this reason, it has been difficult to obtain good visibility at an arbitrary position in the illuminated area.

  The present invention has been made in view of the above situation, and can be used to illuminate an illuminated area on a desk top surface with effective high illuminance and a sufficient amount of light without causing an increase in heat generation or power consumption. Therefore, the object of the present invention is to obtain good visibility as desk lighting regardless of the position of the illuminated area.

The above object of the present invention is achieved by the following configuration.
(1) It has a base installed on the desk surface, a column erected on the base, and a movable support part that is connected to the column and supports the head movably at the tip, and illuminates the table surface A desk lighting device,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
Desk lighting device with

  According to the desk lighting device, the first reflecting portion reflects light from the light emitting diode substantially parallel to the light emitting side and the second reflecting portion is not incident on the first reflecting portion. Can be reflected toward the oblique side (front side on the desk) of the light emitting side. In addition, since the plurality of light emitting diodes are arranged in a line, the entire desk surface can be illuminated with an illuminance distribution that does not rapidly decrease the illuminance from the back side toward the near side. In addition, since the head is supported by a support that is erected on the base via a movable support part, the base can be moved so that the base can be installed at an arbitrary position on the desk surface and easily placed at the desired position on the desk surface. It becomes possible to form an illuminated area.

(2) A desk lighting device that is provided on the bottom surface of a desk book shelf provided at the rear of the desk top surface and illuminates the desk top surface,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
Desk lighting device with

  According to the desk lighting device, the first reflecting portion reflects light from the light emitting diode substantially parallel to the light emitting side and the second reflecting portion is not incident on the first reflecting portion. Can be reflected toward the oblique side (front side on the desk) of the light emitting side. In addition, since the plurality of light emitting diodes are arranged in a line, the entire desk surface can be illuminated with an illuminance distribution that does not rapidly decrease the illuminance from the back side toward the near side. Furthermore, by providing a desk lighting device on the shelf bottom surface of the desk bookshelf provided on the back side of the desk top surface, the reflected light from the second reflecting part is irradiated toward the front part of the desk top surface, As a result, a wide space where no lighting device is arranged is secured, and illumination from the back to the front of the desk surface can be performed with sufficient illuminance.

(3) A hanging type desktop lighting device that is suspended on a ceiling surface directly above the desk top surface and illuminates the desk top surface,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
A hanging type desktop lighting device with

  According to this hanging type desk lamp, the first reflecting portion reflects light from the light emitting diode substantially parallel to the light emitting side, and the second reflecting portion does not enter the first reflecting portion. The light from the light emitting diode can be reflected toward the oblique side (front side on the desk) on the light emitting side. In addition, since the plurality of light emitting diodes are arranged in a line, the entire desk surface can be illuminated with an illuminance distribution that does not rapidly decrease the illuminance from the back side toward the near side. Furthermore, since it is suspended from the ceiling surface by a wire or the like, the installation space for the lighting device is not required on the desk surface, and the lighting device is disposed above one end of the illuminated area, so that As a result, it is possible to form an illuminated area with sufficient illuminance on the desk surface while ensuring a wide space where no lighting device is arranged.

(4) The desk lamp according to any one of (1) to (3),
The desk-top illuminating device in which the said 1st reflection part contains the reflective surface which consists of a paraboloid.

  According to this desk lighting device, the light from the light emitting diode can be condensed and converted into parallel light, and the illuminance can be improved.

(5) The desk lamp according to any one of (1) to (3),
The desk lighting device in which the first reflection unit includes a reflection surface formed of a spheroid surface.

  According to this desk lighting device, the light-collecting diode is arranged at one focal position on the spheroid surface, and the light focusing property is adjusted by setting the other focal position to either the desk top surface or the top and bottom of the desk top surface. Thus, the desired illuminance distribution can be set.

(6) The desk lamp according to any one of (1) to (3),
The desk-top lighting device in which the first reflecting section includes a reflecting surface made of a paraboloid and a reflecting surface made of a spheroid.

  According to this desk-top lighting device, the mixing ratio between the number of reflecting surfaces made of a paraboloid and the number of reflecting surfaces made of a spheroid surface is set to a desired ratio, so that the light condensing property and the light diffusing property are appropriately set. Combined desired illumination distribution can be obtained.

(7) The desk lamp according to any one of (1) to (6),
A table-top lighting device in which the light emitting diodes of the arrayed light source are arranged in a plurality of rows and the arrangement intervals of the light emitting diodes are shifted by a half cycle for each row.

  According to this desk lamp, the light emitting diodes are arranged in a staggered manner, so that a high-density light source arrangement with improved space efficiency is achieved, and the illuminance per unit area can be improved.

(8) The desk lamp according to any one of (1) to (7),
A desk lighting device in which a satin finish is applied to a reflecting surface of at least one of the first reflecting portion and the second reflecting portion.

  According to the desk lighting device, the matte finish is applied, so that the reflected light is diffused and illumination can be performed with a uniform illuminance over a wider range.

(9) The desk lamp according to any one of (1) to (8),
A desk lighting device in which the first reflecting portion and the second reflecting portion are integrally formed.

  According to this desk lamp, the first reflecting portion and the second reflecting portion can be formed by a continuous reflecting surface, and the reflected light of the first reflecting portion and the reflected light of the second reflecting portion are irradiated. A non-uniform portion (illuminance unevenness) due to a large illuminance difference does not occur in the illumination area. In addition, the lighting device can have a compact configuration.

(10) The desk lamp according to any one of (1) to (8),
The second reflecting portion is a plate-like elastic body including the flat reflecting surface and a base having a U-shaped cross section connected to the reflecting surface.
The first illumination unit and the array-shaped light source are inserted into a base of the plate-like elastic body, and are held in the base by the elastic restoring force of the plate-like elastic body.

  According to this desk lamp, since the second reflecting portion is a plate-like elastic body including a flat reflection surface and a base having a U-shaped cross section, the second reflecting portion is inserted into the elastically deformed plate-like elastic body. One reflector and an arrayed light source are positioned and held by the elastic restoring force of the plate-like elastic body. As a result, the relative positions of the array light source, the first reflecting portion, and the second reflecting portion are easily and accurately positioned, and a uniform illuminance distribution is formed.

(11) The desk lamp according to (10),
The flat reflecting surface of the second reflecting portion is a desk lighting device formed with a white painted surface.

  According to this desk lamp, the flat reflection surface is formed of a white painted surface, so that light from the light emitting diode can be reflected with high brightness while having an appropriate light diffusion effect.

(12) The desk lamp according to (10) or (11),
The array light source has a substrate on which a plurality of light-emitting diodes are mounted on the front surface side, and the back surface of the substrate is surface-bonded to the plate-like elastic body via a low heat resistance layer for heat dissipation.

  According to this desk lighting device, the plate-like elastic body generates heat generated by the array-like light source by surface bonding between the plate-like elastic body and the substrate back surface of the array-like light source via the low heat resistance layer for heat dissipation. Therefore, heat can be dissipated with high efficiency, and stable continuous lighting of the light-emitting diode becomes possible.

(13) The desk lamp according to (12),
A desk lighting device in which the low heat resistance layer for heat dissipation is a thermosetting silicone layer.

  According to the desk lighting device, the heat bonding type silicone is applied to the back surface of the substrate, for example, so that a surface bonding structure in which air is surely excluded from the space between the substrate and the second reflecting portion can be easily formed. The heat dissipation effect can be easily obtained with high reliability.

  According to the desk lighting device according to the present invention, it is possible to make the illumination distribution on the desk top surface with high illuminance and uniform illuminance distribution without increasing power generation and power consumption while saving power. It can illuminate uniformly with sufficient high light intensity and sufficient light intensity throughout. In addition, the light superimposed irradiation region having an effective illuminance distribution can be formed over a wide area on the desk surface, and an optimal illuminance pattern can be realized. As a result, favorable lighting performance can be obtained as desk lighting.

It is a schematic explanatory drawing which shows the desk lighting apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing in the YZ plane of the head of a desk-top illuminating device. It is explanatory drawing which represented the side view of the illumination unit to (a), and represents the bottom view to (b). It is a principal part expansion perspective view of an illumination unit. It is a disassembled perspective view of an illumination unit. It is explanatory drawing which shows the optical path of the light source light of an illumination unit. It is the conceptual graph which investigated the relationship between illumination intensity and the distance from a light source according to the presence or absence of a reflective surface, and its kind (alpha), (beta), and (gamma). It is explanatory drawing which shows one structural example when arrange | positioning in a line form using many lighting units. It is a principal part perspective view of the illumination unit provided with the array light source of a staggered arrangement. The head of Example a is (a), the head of Example b is (b), the head of Comparative Example c is (c), the head of Comparative Example d is (d), the head of Comparative Example e It is the block diagram which represented (e). It is a perspective view of the desk lighting device concerning a 3rd embodiment. It is a bottom view of the head of the desk lighting device shown in FIG. It is AA sectional drawing of FIG. It is the perspective view which looked at the lower surface of the illumination unit shown in FIG. 13 up. It is a lighting unit exploded perspective view shown in FIG. It is the external view which represented the bottom view of the illumination unit shown in FIG. 14 by (a), front view (b), and planar view (c). It is a perspective view of a lighting block alone. Appearance of lighting block as (a), left side view (b), plan view (c), right side view (d), back view (e), bottom view (f) FIG. It is a side view showing the 1st reflection part holding structure of the 2nd reflection part. It is explanatory drawing which shows the optical path of the desk lighting apparatus which concerns on 3rd Embodiment. It is a schematic diagram showing the illumination distribution by the desk lighting apparatus shown in FIG. It is the structure explanatory view which expressed the lower surface view of the head which arranged 4 rows of LEDs in a zigzag, and the BB section was expressed in (b). It is a schematic explanatory drawing which shows the desk lighting apparatus of the learning desk which concerns on 4th Embodiment. It is a schematic explanatory drawing which shows the hanging type desk-top illuminating device which concerns on 5th Embodiment. It is explanatory drawing which shows the illuminance distribution of (a), (b), (c) when the 2nd focus of the reflective surface which consists of a spheroidal curved surface is a different position, respectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Desk surface, 17 ... Head, 29 ... LED (light emitting diode), 41 ... 1st reflection part, 41A ... Reflective surface which consists of paraboloids, 42, 72 ... 2nd reflection part, 42A ... Flat plate-like reflection Surface 61, base 63, support column 65, movable support unit 77 light emitting unit (array light source) 81 plate elastic body 81 a base unit connecting flat reflecting surface 100, 200 desktop Illuminating device, 101 ... desktop shelf, 300 ... learning desk desktop lighting device, 400 ... suspended desktop lighting device, S ... illuminated area

DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a desk lamp according to the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic explanatory view showing a desk lamp according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the head on the YZ plane.
The desktop lighting device 100 according to this embodiment is configured to illuminate the desk top surface 11 and mainly includes a drive unit (not shown), a support column 13, a movable support unit 15, and a head 17. . In the figure, 16 is a support arm, 19 is a desk, 21 is a PC (personal computer) monitor placed on the desk top surface 11, and 23 is a PC keyboard.

  The drive unit supplies drive power for light emission to the illumination unit 25 provided on the head 17, and for example, a full range transformer or the like can be used. The drive unit is connected to a commercial power source, for example, converts the power of AC110V to 220V, 50Hz to 60Hz, etc. into a drive voltage of DC12V (any voltage such as DC6V or DC24V, or alternating current) and lighting unit 25.

  The illumination unit 25 is unitized by arranging LEDs in a line in a row (this is referred to as an “array light source”). In the present embodiment, the illumination unit 25 includes a back plate 27, a light emitting unit 33 in which a large number of LEDs 29 serving as a light source are linearly disposed on a wiring board (printed circuit board) 31 serving as a base, and a reflecting mirror member. 35. The back plate 27 is detachably assembled to the reflector member 35 with the wiring board 31 sandwiched between the back plate 27 and the reflector member 35.

Next, the lighting unit 25 will be described.
3A and 3B are explanatory views showing a side view and a bottom view of the illumination unit, FIG. 4 is an enlarged perspective view of a main part of the illumination unit, and FIG. 5 is an exploded perspective view of the illumination unit.
As shown in FIG. 3A, the illumination unit 25 has a back plate 27 assembled to the reflecting mirror member 35, and has a height H in this state. The height H is about 15 mm in the present embodiment, and is significantly thinner than when an incandescent bulb or a fluorescent lamp is used as the light source. Therefore, even if it is located above the desk 19, the presence of the lighting unit 25 does not get in the way. If the height H of the illumination unit 25 is too low, the later-described deflection characteristics of the reflecting mirror member 35 are impaired. If the height H is too high, an installation space is required and the degree of freedom in arrangement of the illumination unit 25 is reduced.

  As shown in FIGS. 2 and 3A and 3B, the reflecting mirror member 35 is formed in an elongated plate-like mounting base portion 37 (see FIG. 5) and is formed integrally with the mounting base portion 37 at a central position. A first reflecting portion formed with a plurality of reflecting surfaces (hereinafter also referred to as “parabolic mirrors”) 41A having an opening and having a parabolic surface whose light emission side is expanded (a total of 16 in this embodiment) 41A. 41 and a perspective view shown in FIG. 4, a flat reflecting surface that is integrally provided on the light emitting side further than the first reflecting portion 41 and is parallel to the arrangement direction of the plurality of parabolic mirrors 41A. (Hereinafter also referred to as “flat plate mirror”) and a second reflecting portion 42 formed with 42A. The reflecting mirror member 35 is a resin molded product integrally formed by injection molding, and at least the light reflecting surfaces of the first reflecting portion 41 and the second reflecting portion 42 are subjected to coating processing by aluminum vapor deposition or the like. Is forming. By forming the first reflecting portion 41 and the second reflecting portion 42 integrally, the reflecting mirror member 35 can be made compact, and a continuous reflecting surface can be formed, and the reflection of the first reflecting portion 41 can be formed. A nonuniform portion (illuminance unevenness) due to a large difference in illuminance does not occur in the illuminated area S (see FIG. 1) irradiated with light and the reflected light of the second reflecting portion 42. Further, the surface treatment of the light reflecting surface is not limited to this, and other conventional means can be used.

  As shown in FIG. 5, the back plate 27 includes a flat-shaped base portion 311 and a plurality of locations in the longitudinal direction of the base portion 311 (5 locations in the present embodiment) on the inner surface of the base portion 311. 31 includes a rib 312 that supports the back surface side of 31, and a lock claw 313 that engages with the reflecting mirror member 35. The lock claw 313 is formed in a hook shape having a vertical cross section of “U”.

  The wiring board 31 is composed of a printed board such as glass epoxy or paper phenol, for example, and a plurality of (16 here) corresponding to the individual parabolic mirrors 41A along the longitudinal direction of the reflecting mirror member 35. LED 29 is mounted. A lead wire L is drawn out from one end of the wiring board 31 and connected to a drive unit (not shown). Since the wiring board 31 of this embodiment is a single-sided module, it is a safe module that is easy to find a problem when a failure occurs and has excellent maintainability.

  The mounting base 37 has brackets 351 for fixing the lighting unit 25 at both ends in the longitudinal direction, and engaging portions with which the locking claws 313 of the back plate 27 are engaged on both sides orthogonal to the longitudinal direction. 352 is provided. Accordingly, the wiring board 31 is sandwiched between the reflecting mirror member 35 and the back plate 27, and the back plate 27, the wiring board 31, and the mounting base 37 of the reflecting mirror member 35 are detachably assembled by the snap action of the lock claw 313. It is done.

  The first reflector 41 has a curved surface shape including a paraboloid in which the parabolic mirror 41A has the LED 29 as a focal position, and most of the emitted light from the LED 29 at the focal position of the paraboloid is parallel. Light (collimated light) travels toward the desk surface 11. The parabolic mirror 41A of the first reflecting portion 41 will be described in detail later, but is not limited to a parabolic shape, and is formed by a curve such as a spheroid or hyperbola, for example. It may be a concave surface.

  As shown in FIG. 2, the second reflecting portion 42 is formed with a flat plate mirror 42 </ b> A on one side in a direction orthogonal to the direction in which the parabolic mirrors 41 </ b> A are arranged. That is, the flat plate mirror 42 </ b> A is disposed only on the back side of the front surface 11 and the back side of the desk surface 11 centering on the LED 29. In terms of the relationship with the illuminated area S, it is arranged on the far side opposite to the near side in the direction orthogonal to the row direction of the LEDs 29 in the illuminated area S on the desk top surface 11.

  As shown in FIG. 2, when the back plate 27, the wiring board 31, and the mounting base 37 (reflecting mirror member 35) are assembled to each other, the LED 29 is placed at the focal position of the parabolic mirror 41A of the first reflecting portion 41 as described above. The light emitting surface is located. Although not shown in the figure, the reflecting mirror member 35 has discretely arranged surfaces in contact with the back surface of the wiring board 31, so that the light emitting surface of the LED 29 is the focal position of the parabolic mirror 41A. The height of the contact surface is adjusted. That is, when the wiring board 31 is placed in the board receiving position formed on the reflecting mirror member 35, the height is set so that the rib 312 of the back plate 27 presses the wiring board 31 against the contact surface. Yes.

  Therefore, the focal position of the parabolic mirror 41A and the position of the light emitting surface of the LED 29 can be easily matched with high accuracy by simply combining the back plate 27, the wiring board 31, and the mounting base 37 (reflecting mirror member 35). Can do. With this configuration, for example, it is possible to easily assemble without using fastening means such as screws, reduce the number of parts, reduce the steps for assembly and adjustment, and improve productivity.

Next, optical characteristics relating to the illumination unit 25 having the above-described configuration will be described with reference to FIGS.
As described above, the reflecting mirror member 35 of the illumination unit 25 includes the first reflecting portion 41 and the second reflecting portion 42 formed continuously. The base end portion of the first reflecting portion 41 has the LED 29. An opening 43 for arranging the light emitting surface at the focal position of the parabolic mirror 41A is provided. The parabolic mirror 41A of the first reflecting unit 41 has a reflecting surface made of a parabolic surface with the light emitting surface of the LED 29 as a focal position, and the light from the LED 29 reflected by the first reflecting unit 41 is the desk surface. 11 (refer to FIG. 1) and proceed to be substantially parallel (collimated). As a result, the light reflected by the parabolic mirror 41A illuminates the area directly below the LED 29 on the desk top surface 11 and its periphery, as shown in FIG.

  On the other hand, the second reflecting portion 42 is provided with a flat plate mirror 42 </ b> A so as to continuously continue from a part of the first reflecting portion 41 and at an inclination angle θ that expands toward the desk surface 11. That is, the flat plate mirror 42A of the second reflecting portion 42 has a flat plate shape arranged along the direction parallel to the arrangement direction of the parabolic mirror 41A, that is, the arrangement (X) direction of the LEDs 29. Yes.

  The flat plate mirror 42A of the second reflecting portion 42 is disposed only on the back side of the front side 11 and the back side of the desk top surface 11 centering on the light emitting diode. Thus, unnecessary light (light of the cut region CT) traveling in this direction is reflected to the near side so as not to leak further from the back side of the desk top surface 11 (see FIG. 1).

  Furthermore, as shown in FIG. 6, the flat plate mirror 42 </ b> A receives a part of the light from the LED 29 that is not incident on the first reflecting portion 41 and is close to the optical axis (center), and receives the desk surface 11. Is reflected toward the front (Y) direction. Thus, the illuminance pattern in which the light reflected by the flat plate mirror 42A is asymmetrical from the back side to the front side with respect to the position directly below the LED 29, that is, the front side (illumination) of the back side (illumination area P1) of the desk top surface 11 Illuminate with a distribution in which the illumination area is shifted to the area P2).

  Thus, the 1st reflection part 41 has the reflective surface area | region M1, and the 2nd reflective part 27 has the reflective surface area | region M2 formed continuously from the reflective surface area | region M1. For this reason, the light reflected by the 1st reflection part 41 and the 2nd reflection part 42 becomes a wide illumination light, and is irradiated to the to-be-illuminated object on the desk surface 11 equally. In addition, since the lighting unit 25 is installed on the back side of the desk top surface 11, the desk-top space is widened and is difficult to interfere. Further, the reflecting mirror member 35 prevents light from leaking outward from the flat plate mirror 42 </ b> A of the second reflecting portion 42. That is, the plane plate mirror 42A can reduce light leakage to the back side of the desk top surface 11 so that the light protrudes from the back side of the desk top surface 11 and blocks the light component going backward. For example, as shown in FIG. 1, it is possible to reliably prevent the illumination light from being applied to the monitor 21 placed on the rear part of the desk top surface 11 and to reduce the visibility due to the reflection of the illumination light on the monitor display surface. Is prevented.

Note that the opening angle θ of the flat plate mirror 42A with respect to the optical axis of the LED 29 depends on the relationship from the desk top surface 11 to the head 17 but further satisfies the requirements described above, that is, the following requirements. Is set. That is,
(1) It has an illuminance distribution that is irradiated so as to compensate for a non-illuminated region of the desk top surface 11 that has not been irradiated by the first reflecting portion 41.
(2) Illumination light should reach the front of the desk top surface 11 as much as possible.
(3) The angle is set so as not to protrude from the desk top surface 11 which becomes a desired illuminated area (prevention of glare). Therefore, in the present embodiment, the inclination angle of the flat plate mirror 42A is set in the range of 13 degrees to 18 degrees with respect to the optical axis of the LED 29.

The element of the LED 29 used in the present embodiment itself has a wide emission angle such as 120 °, but the light is emitted by optimally setting the shape of the parabolic mirror 41A according to the emission angle. It can correct | amend so that the ratio which goes to the 1st reflection part 41 among the lights, is caught by the 1st reflection part 41, and contributes to parallel light conversion may not become high too much. By such correction, the effect of uniformizing the illuminance distribution is enhanced in the range from the back side to the front side of the desk surface 11.
On the other hand, even if the light component which goes to the 2nd reflection part 42 among the lights radiate | emitted from LED29 increases, the length of Z direction and the opening angle (theta) (refer FIG. 2) of the 2nd reflection part 42 are set optimally. In addition, the light component irradiated from the position directly under the LED 29 to the front side of the desk top surface 11 can be increased without protruding from the desired illuminated area of the desk top surface 11. Thereby, sufficient illumination intensity can be provided to visual recognition objects, such as the keyboard 23 and document which were mounted in the near side of the desk surface 11. FIG.

Next, the light reach distance of the illumination unit 25 will be described.
FIG. 7 is a conceptual graph in which the relationship between the illuminance by the light source of the illumination unit 25 and the distance from the light source in the present embodiment is examined according to the presence or absence of the reflecting surface and the types α, β, and γ. In addition, the area | region which becomes more than the limit illumination intensity (delta) in each graph (alpha), (beta), (gamma) is an area | region which has the effective illumination intensity which can be utilized for desk lighting.

The area having sufficient illuminance when the object to be viewed on the desk top surface 11 is illuminated by the desk lighting device 100 is not only the width direction (X) of the desk top surface 11 but also the illumination light in the front direction (Y). The reach of is greatly related.
As shown in FIG. 7, assuming that the limit range in which the desk top surface 11 can be illuminated with sufficient illuminance is the range above the line indicated by δ in the figure, when the reflecting mirror member 35 is not provided (α), it is directly under the light source. If the distance L1 is exceeded, the illuminance is insufficient. On the other hand, when only the parabolic mirror of the first reflection unit 41 is provided (β), the illuminance is within the allowable range at the distance L2, but the illuminance is insufficient when the distance L2 is exceeded. On the other hand, when both the parabolic mirror 41A of the first reflecting portion 41 and the flat plate mirror 42A of the second reflecting portion 42 as in the present invention are provided (γ), the distance is greatly separated from the distances L1 and L2. No illuminance shortage occurs until L3. Thus, in the case of the configuration according to the present invention, the light reaching distance to the near side of the desk top surface 11 can be dramatically increased by the synergistic effect of the parabolic mirror 41A and the flat plate mirror 42A.

  As described above, according to the lighting unit 25 and the desk lighting device 100 including the lighting unit 25 according to the present embodiment, the light flux from the LED 29 is reflected by the first reflecting portion 41 and substantially parallel to the desk top surface 11. Turn into. On the other hand, of the light flux from the LED 29 that has not entered the first reflecting portion 41, the light that has passed through the second reflecting portion 42 without being irradiated is projected while being diffused directly below the front surface 11 and toward the front portion. Is done. Further, the light irradiated and reflected on the second reflecting portion 42 is projected toward the front portion of the desk surface 11. As a result, the illuminated area S of the desk top surface 11 can be enlarged toward the front portion of the desk top surface 11.

And since LED29 itself used as a light source is supplied cheaply, the desk-top illuminating device 100 whole can be produced at low cost. Furthermore, since the power consumption of the light source is significantly lower than incandescent bulbs and fluorescent lamps, the running cost can be reduced. Specifically, under the same illuminance, the LED 29 consumes 1/6 that of a neon lamp and 1/8 that of a fluorescent lamp. This contributes to improving the energy efficiency of lighting and reducing the influence on environmental problems such as CO ₂ emission reduction. Moreover, since the LED 29 is driven at a low voltage, troubles after installation such as a shock hazard hardly occur. Furthermore, since most of the emitted light has a wavelength pattern limited to a range from approximately 450 nm blue to 700 nm red, the LED used here contains almost no ultraviolet rays of 380 nm or less and infrared rays exceeding 760 nm. In addition, the object to be illuminated is not damaged.

  Moreover, since the illumination unit 25 of this embodiment is provided with the reflecting mirror which consists of the 1st, 2nd reflection parts 41 and 42 in the light emission side of LED29, compared with the case where it provides in the back side of LED29, The lighting unit 25 can be made thin. This is particularly advantageous when the head 17 is placed in the space on the desk top surface 11 where the space for placing the head 17 is limited. In addition, the optical system can be simplified and the apparatus cost can be reduced as compared with a configuration in which the optical path is deflected by a lens or the like. In addition, the light use efficiency can be prevented from being lowered due to light absorption or the like during lens transmission.

FIG. 8 is an explanatory diagram showing a configuration example when a large number of illumination units are used and arranged in a line.
The LED 29 is configured as a light emitting unit 33 in the form of an array of a plurality of units. However, as shown in FIG. 8 as an example of installation, a connector 53 is interposed in a part of a flat cable 51 drawn from a commercial power source. By doing so, a plurality of illumination units 25 can be easily arranged. For example, when three lighting units 25 are used in one head 17 and the lighting units are similarly installed in other heads 17, the three lighting units 25 in the illustrated example are connected to one connector for connection. The wiring is drawn from 53 and installed, and the other head 17 is installed by drawing the wiring from another connector for connection. In other words, the head 17 and the other head 17 are connected by the flat cable 51. The lighting units 25 on the same desk top surface 11 may be connected in parallel as in the illustrated example, but wiring can be simplified by connecting the lighting units 25 directly in a chain shape.

  Further, the reflecting mirror member 35 may be a curved surface formed on the basis of an arbitrary curve such as a hyperbola, for example, without making the reflecting surface of the parabolic mirror 41A of the first reflecting portion 41 a strict paraboloid. Good. In any case, it may be a curved surface that approximates a paraboloid or the like, or may be a paraboloid formed as a whole by combining fine plane mirrors.

  Here, the illumination unit 25 in the present embodiment may be formed in a satin shape by providing a number of fine irregularities on each reflection surface of the reflecting mirror member 35, for example. By using at least part of the reflective surface as a satin finish, the range in which the illuminance is uniform becomes wider compared to when the satin finish is not applied, and a uniform illumination over a wider area is possible with a single lighting unit. Is possible. In addition, the occurrence of uneven color of illumination light is also prevented.

(Second Embodiment)
Next, a second embodiment of the lighting unit according to the present invention will be described. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.
FIG. 9 is a perspective view of a main part of an illumination unit including a staggered array of light sources.
The lighting unit 25A of the present embodiment is for performing a wide range of desk top lighting with higher brightness, and in the lighting unit 25 shown in the first embodiment, an array in which a plurality of LEDs 29 are arranged in series. The light emitting sections 33 are arranged in parallel in a plurality of rows (two rows in this embodiment), and the light emitting diodes are arranged in a zigzag manner by shifting the light emitting diode arrangement interval by a half cycle for each light emitting diode row. Yes. The arrangement interval of the LEDs 29 in each row of the illumination unit 25A is set so that the total illuminance distribution obtained by superimposing the intensity of irradiation light from the light emitting units 33 in each adjacent row is as uniform as possible.

  According to this configuration, the illumination unit 25A can array the LEDs 29 in a plurality of rows, so that the illuminance can be improved and the range in which the illuminance is uniform can be expanded. It can be illuminated with high brightness.

  As described above, the structure of the reflecting mirror member can be appropriately changed, and other changes may be made as follows. That is, the arrangement of the LEDs 29 is linear one row and two rows, but in the case of multiple rows of two or more rows, an appropriate regular arrangement (such as a square arrangement) other than the staggered arrangement, or a random arrangement. It is good also as a structure. Further, as described above, the deflection state of the light emitted from the LED 29 is adjusted by changing the opening angle θ (similar to θ in FIG. 2) of the flat plate mirror 42A of the second reflecting portion 42 with respect to the optical axis of the LED 29. can do.

Next, examples a and b of the present invention and comparative examples c and d having the configurations shown in FIGS. 10A to 10E on the same installation surface as the desk top surface 11 in the first embodiment, respectively. , E was installed, and a comparative experiment was conducted to examine the illuminance distribution when the desk surface 11 below 500 mm was illuminated.
FIG. 10 shows the head of Example a (a), the head of Example b (b), the head of Comparative Example c (c), the head of Comparative Example d (d), and Comparative Example e. It is the block diagram which represented the head of (e).

  Examples a and b use the one in which the second reflection part 42 extended from the first reflection part 41 is formed only on one side, and the comparative examples c, d, and e have the same configuration as that of the first embodiment. In the desk lighting device 100, a pair of second reflecting portions 42 formed on both sides was used.

The height of the reflecting mirror member in each of Examples a and b and Comparative Examples c to e is as follows.
Example a h1 = 7.9 mm, h2 = 6.75 mm, θa = 18 degrees Example b h1 = 7.9 mm, h2 = 6.00 mm, θb = 13 degrees Comparative example c h1 = 7.9 mm, h2 = 6 .75mm, h3 = 14.65mm
Comparative Example d h1 = 6.3 mm, h2 = 6.00 mm, h3 = 12.30 mm
Comparative Example e h1 = 5.5 mm, h2 = 6.00 mm, h3 = 11.50 mm
Both structures have a satin finish on the reflective surface.

In the example a, the height of the reflecting mirror member 35 is 14.65 mm, and in the example b, the height of the reflecting mirror member 35 is 13.9 mm cut by about 5%.
On the other hand, in Comparative Example c, the height of the reflecting mirror member 35 is the same as that of Example a, and in Comparative Example d, the height of the reflecting mirror member 35 is cut by 20% compared to Comparative Example c. Furthermore, in the comparative example e, the height of the reflecting mirror member 35 is cut by 30% compared to the comparative example c.

In addition, the illuminance measurement here was performed by installing the above five models of illumination devices in a dark room, and measuring the illuminance at each preset measurement position with an illuminance measurement device (Yokogawa Instruments Corp. Model No. 51002). .
The results when the illuminance measurement is performed in this manner are shown in the following table.

  As described above, in Example a, an illuminance of 23 [lx] is secured even in the front part (position at a distance of 400 mm) that is farthest in the Y direction from directly below the light source, and in Example b, the Y direction is also from directly below the light source. An illuminance of 19.5 [lx] was obtained even at the frontmost part (position at a distance of 400 mm).

  On the other hand, in Comparative Example c, it was confirmed that an illuminance of 36 [lx] was obtained at a position 300 mm away from directly under the light source in the Y direction, but it attenuated rapidly to 2 [lx] at a position 400 mm away. There was found. Thereby, in the forefront part (400 mm), the illuminance is insufficient.

  In Comparative Example d, almost the same result as in Comparative Example c was obtained. That is, it was found that an illuminance of 35 [lx] was obtained at a position 300 mm away from directly below the light source, but abruptly attenuated to 4 [lx] at a position separated by 400 mm. That is, as in Comparative Example c, good desk top illumination cannot be performed at the forefront (400 mm).

  Furthermore, in Comparative Example e, it was confirmed that the illuminance distribution was improved as compared with Comparative Examples c and d. That is, it has been found that an illuminance of 36 [lx] is obtained at a position 300 mm away in the Y direction from directly below the light source, and attenuates to 12 [lx] at a position 400 mm away. However, compared with Examples a and b, the illuminance at the forefront (400 mm) is low, and the desk top illumination cannot be performed with sufficient illuminance.

(Third embodiment)
Next, a third embodiment of the lighting unit according to the present invention will be described. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.
11 is a perspective view of a desk lamp according to the third embodiment, FIG. 12 is a bottom view of the head of the desk lamp shown in FIG. 11, and FIG. 13 is a cross-sectional view taken along line AA of FIG.
As shown in FIG. 11, the desk lighting device 200 includes a base 61 installed on the desk top surface 11, a column 63 erected on the base 61, and a head 17 </ b> A that is connected to the column 63 and movable at the tip. And a movable support portion 65 to support.

The base 61 is provided with a drive unit (not shown), and commercial power is supplied to the drive unit through a power line 67 connected to the base 61. A power switch 69 and a light amount adjustment wheel 70 are provided on the upper surface of the base 61. The power switch 69 opens and closes a power supply circuit that supplies a drive current from the drive unit to the LED 29 by a pressing operation. The light amount adjusting wheel 70 adjusts the luminance of the light emitting unit accommodated in the head 17A by a rotating operation.
In addition, as shown in FIG. 12, the lighting unit 25 </ b> B is accommodated in the head 17 </ b> A, and the lighting unit 25 </ b> B includes two lighting blocks 71 and 71 in which the first reflecting portions 41 are arranged in a staggered manner, and a second reflecting portion 72. Have The illumination unit shown in FIG. 9 is different in that the first reflection part 41 and the second reflection part 42 are formed by separate members.
As shown in FIG. 13, the second reflecting portion 72 is a plate-like elastic body 81 including a flat reflecting surface 72A and a base portion 81a having a U-shaped cross section connected to the reflecting surface 72A. The part 41 and the wiring board 31 serving as an array light source are inserted into the base 81 a of the plate-like elastic body 81.

Here, the illumination unit 25B will be described.
14 is a perspective view of the lighting unit shown in FIG. 13 as viewed from the bottom, FIG. 15 is an exploded perspective view of the lighting unit shown in FIG. 14, and FIG. 16 is a bottom view of the lighting unit shown in FIG. It is the external view which represented a), front view by (b), and planar view by (c).
The lighting unit 25 </ b> B accommodates the two lighting blocks 71 and 71 in the second reflecting portion 72 by connecting them linearly in the longitudinal direction. The two illumination blocks 71 and 71 constitute a light emitting unit 77 that is an array light source in which a plurality (9 in the present embodiment) of the first reflecting units 41 are arranged in two rows of lines. The first reflecting portion 41 is provided on the light emitting side of the light emitting portion 77 corresponding to each of the LEDs 29, and has a curved surface shape that expands toward the desk top surface 11.

  The second reflecting portion is provided along the column direction of the LEDs 29 on the light emitting side of the first reflecting portion 41. In the second reflecting section 72, a flat reflecting surface (planar mirror) 72A that reflects the light from the LED 29 toward the light emitting side is disposed only on one side in a direction orthogonal to the LED arrangement direction. Further, when expressed in relation to the illuminated area S on the desk top surface 11, the second reflecting portion 72 is disposed only on one side which is the back side in the direction orthogonal to the LED arrangement direction in the illuminated area S.

  Each lighting block 71, 71 is formed with Z-shaped step portions 73a, 73b at both ends in the longitudinal direction, and the step portions 73a, 73b are combined with each other and connected linearly. As shown in FIG. 15, the plurality of connected illumination blocks 71 and 71 are assembled into the rectangular parallelepiped shown in FIG. 16 by combining the end pieces 75 that coincide with the stepped portions 73a and 73b at both ends in the longitudinal direction. It has become.

FIG. 17 is a perspective view of the lighting block alone, FIG. 18 is a front view of the lighting block (a), a left side view (b), a plan view (c), a right side view (d), and a rear view ( e) An external view showing the bottom view (f) is shown.
A single illumination block 71 shown in FIG. 17 is a resin molded product integrally formed by injection molding, and at least the light reflecting surface (parabolic mirror 41A) of the first reflecting portion 41 is coated by aluminum deposition or the like. Is applied to form a mirror surface. In addition, the parabolic mirror 41A may be formed in a satin shape having a number of fine irregularities as described above. Further, the illumination block 71 is provided with apertures 79 shown in FIG. 18 corresponding to the respective LEDs 29, and the apertures 79 penetrate the illumination block 71 in the thickness direction and represent the LEDs 29 mounted on the wiring board 31. It is possible to go out.

Here, FIG. 19 shows a side view showing the first reflecting portion holding structure of the second reflecting portion.
As shown in FIG. 19, in the second reflecting portion 72 in the present embodiment, the base 81 a of the plate-like elastic body 81 connected to the flat plate mirror 72 </ b> A has a U-shaped cross section, and the plate-like elastic body 81. The inside is an accommodation space 83 for the illumination block 71. The base part 81a of the plate-like elastic body 81 is expanded so as to widen the inclination angle of the flat plate mirror 72A and bent outward, whereby the first reflecting part (illumination block 71) inserted into the accommodation space 83, wiring The substrate 31 is locked with the bent portion 85 as a drop-off preventing hook, and is accommodated with a predetermined holding force by the elastic restoring force of the plate-like elastic body 81. That is, the illumination block 71 can be easily assembled to the second reflecting portion 72 by the snap action of the flat plate mirror 72A.

  That is, in the illumination unit 25B, the second reflecting portion 72 connects the flat plate mirror 72A and the base portion 81a made of the plate-like elastic body 81 having a U-shaped cross section, and is elastically deformed to the plate-like elastic body 81. The illumination block 71 inserted inside is positioned and held so as to be immovable by the elastic restoring force of the plate-like elastic body 81 and accommodated. Thereby, the relative position of LED29, the 1st reflection part 41, and the 2nd reflection part 72 is positioned, and a highly accurate optical axis alignment can be performed easily.

  The plate-like elastic body 81 is made of a sheet metal member made of metal (for example, aluminum, stainless steel, etc.), and the flat reflection surface of the second reflecting portion 72 is formed of a white painted surface. The light from the LED 29 can be reflected with high brightness while having an appropriate light diffusion effect.

  Further, in the illumination unit 25B, the heat dissipation low thermal resistance layer 87 is applied to the surface of the wiring board 31 assembled on the upper surface of the illumination block 71. The low heat resistance layer 87 for heat dissipation can be formed by applying thermosetting silicone. This heat-curing silicone includes heat dissipation silicone SCV-22 (thermal conductivity 0.92 W / mk) manufactured by Sanhayato Co., Ltd., and heat dissipation silicone RTV rubber X-32-2129 manufactured by Shin-Etsu Chemical Co., Ltd. (thermal conductivity). A rate of 0.9 W / mk) can be preferably used. The applied heat radiating silicone 87 is filled in the gap between the illumination block 71 and the plate-like elastic body 81 when the illumination block 71 is held in the accommodation space 83 of the second reflecting portion 72. That is, a surface connection structure is formed in which air is excluded from between the illumination block 71 and the plate-like elastic body 81. Thereby, the thermal conductivity from the illumination block 71 and the wiring board 31 is enhanced, and the amount of heat generated by the light emission of the LED 29 can be dissipated with high efficiency by using the plate-like elastic body 81, so that the LED 29 can be stably continuous. Can be lit.

Next, the lighting effect by the desk lighting device having the above configuration will be described.
FIG. 20 is an explanatory diagram showing an optical path of the desk lamp according to the third embodiment, and FIG. 21 is a schematic diagram showing an illuminance distribution of the lighting unit shown in FIG.
In this desk lighting device 200, as shown in FIG. 20, the first reflecting portion 41 reflects the light from the LED 29 substantially parallel to the light emitting side, and the second reflecting portion enters the first reflecting portion. The light or the like from the light emitting diode that has not been reflected can be reflected toward the oblique side (front side on the desk) of the light emitting side. Further, by arranging the plurality of LEDs 29 in a line shape, it is possible to illuminate the entire desk surface with an illuminance distribution in which the illuminance does not rapidly decrease from the back side toward the near side. In addition, since the head is supported by a support that is erected on the base via a movable support part, the base can be moved so that the base can be installed at an arbitrary position on the desk surface and easily placed at the desired position on the desk surface. It becomes possible to form an illuminated area.

FIG. 21 schematically shows the illuminance distribution of the desk lamp of the present embodiment.
As shown in FIG. 21, the illumination light from the desk lighting device 200 of the present embodiment does not rapidly decrease in illuminance toward the front side of the desk, with the position immediately below the light source as a border, and the back side of the desk is The illuminated area S has an illuminance distribution in which the illuminance is suddenly reduced, and the illuminated area is widened from directly under the light source to the front side of the desk.

  Further, by installing the base 61 at an arbitrary position on the desk top surface, the illuminated area S having a sufficient area can be easily formed at a desired position on the desk top surface. In FIG. 21, reference numeral 91 denotes an illuminated region having a configuration in which the second reflecting portion 72 is provided on both sides, and 93 denotes an illuminance distribution having a configuration in which the first reflecting portion 41 and the second reflecting portion 72 are not provided. In either case, the illuminated area up to the front side of the desk surface cannot be illuminated.

  Therefore, according to the desk lighting device 200 having the above-described configuration, the light emitting section 77 that is an array light source in which the LEDs 29 are arranged in a line, and the first reflecting section that expands toward the desk top surface 11 corresponding to each of the LEDs 29. 41 and the second reflecting portion 72 disposed only on one side in the direction orthogonal to the column direction of the LEDs 29 on the light emitting side of the first reflecting portion 41, the first reflecting portion 41 receives the light from the LED 29. By reflecting the light from the LED 29 that is substantially parallelized and reflected toward the light emitting side, and the second reflecting portion 72 is not incident on the first reflecting portion 41, it is possible to save power and achieve high illumination. It is possible to uniformly illuminate the area up to the front side of the, and uniformly illuminate the entire illuminated area S on the desk top surface 11 with high illuminance without causing an increase in the amount of heat generation or power consumption.

  Further, since the plurality of LEDs 29 are arranged in a line, the illuminated area S having an illuminance distribution that does not rapidly decrease in illuminance can be widened from the position directly below the light source to the front side of the desk, and practically sufficient illuminance. Can be formed in a large area of the desk top surface 11. As a result, when the desk lighting device 200 is used for desk lighting, it is possible to obtain good visibility of the illumination target.

Next, a modified example of the above desk lamp will be described.
FIG. 22 is an explanatory diagram of a configuration in which a bottom view of a head in which four rows of LEDs are arranged in a staggered manner is shown in (a) and a BB cross section is shown in (b).
The desk lighting device 200 according to the third embodiment has been described in the configuration example including the head 17A in which the lighting blocks 71 and 71 are linearly connected. In addition, as illustrated in FIG. Illumination blocks 71 and 71 may be arranged in parallel on the head 17B. With such a parallel arrangement configuration, the number of LEDs 29 can be increased in the depth direction of the desk top surface 11, so that the emitted light from the LEDs 29 can be further expanded from directly under the array light source to the front side of the desk. Can do. In addition, the width of the head can be made compact, and the degree of freedom in installing the lighting device is increased. In addition, although LED row | line | column is shown here as 4 rows, it can be set not only to this but arbitrary multiple rows | lines.

(Fourth embodiment)
FIG. 23 is a schematic explanatory diagram showing a desk lighting device for a learning desk according to the fourth embodiment. In the present embodiment, the same parts as those in the third embodiment are denoted by the same reference numerals, and redundant description is omitted.
The desk lighting device 300 for a learning desk according to this embodiment is provided on the lower surface of the shelf 103 of the desk book shelf 101 provided at the rear of the desk top 11 and illuminates the desk top 11 of the desk 19. A bookcase or the like on which a book 105 is placed is provided on an upper part of the desktop bookcase 101.

  The desk lighting device 300 is provided on the light emitting side of the light emitting unit 77 corresponding to each of the plurality of LEDs 29 and the arrayed light source (light emitting unit 77) in which the plurality of LEDs 29 are arranged in at least one line. A first reflecting portion 41 having a curved surface shape that is widened toward 11, and a light emitting side of the first reflecting portion 41 that is provided along the column direction of the LEDs 29 and that directs the light from the LED 29 toward the light emitting side. The flat plate mirror 72 </ b> A that reflects light is provided with a second reflecting portion 72 that is disposed only on one side in a direction orthogonal to the LED arrangement direction.

  According to the desk lighting device 300 of the learning desk, in addition to the same effect as the desk lighting device of each of the above-described embodiments, by being provided on the shelf plate 103 of the desk book shelf 101 provided at the rear of the desk top surface 11. The reflected light from the second reflecting portion 72 is irradiated toward the front portion of the desk top surface 11, and a wide space in which no lighting device is disposed is secured above the desk top surface, while the back of the desk top surface 11 extends to the front portion. It can be illuminated with sufficient illuminance.

(Fifth embodiment)
FIG. 24 is a schematic explanatory view showing a hanging type desk lamp according to a fifth embodiment. In the present embodiment, the same parts as those in the third embodiment are denoted by the same reference numerals, and redundant description is omitted.
A suspended desktop lighting device 400 according to this embodiment is suspended from a ceiling surface 111 by a wire 113 including electric wires and the like, and illuminates the desk surface 11.

  The desk lighting device 400 is provided on the light emitting side of the light emitting unit 77 corresponding to each of the plurality of LEDs 29 and an array light source (light emitting unit 77) in which a plurality of LEDs 29 are arranged in at least one line. A first reflecting portion 41 having a curved surface shape that is widened toward 11, and a light emitting side of the first reflecting portion 41 that is provided along the column direction of the LEDs 29 and that directs the light from the LED 29 toward the light emitting side. The flat plate mirror 72 </ b> A that reflects light is provided with a second reflecting portion 72 that is disposed only on one side in a direction orthogonal to the LED arrangement direction.

  According to the hanging type desk lighting device 400, in addition to the same effects as the desk lighting devices of the above-described embodiments, the hanging type desk lighting device 400 is hung by the wire 113 from the ceiling surface 111. Since the space is not required and is disposed above one end side of the illuminated area S, a wide space where no illumination device is disposed is secured above the desk surface, and the illuminated area S having sufficient illuminance on the desk surface 11 is secured. Can be formed.

In the desk lighting device of each embodiment explained above, although the reflective surface of the 1st reflective part of a reflector member was explained as a paraboloid, arbitrary concave curved surfaces other than this may be sufficient.
Here, an example in which the reflecting surface of the first reflecting portion 41 is a spheroidal curved surface and an example in which a spheroidal curved surface and a paraboloid are mixedly arranged will be described.
FIG. 25 is an explanatory diagram showing the illuminance distribution of (a), (b), and (c) when the second focal points of the reflecting surface formed of a spheroidal surface are at different positions. In addition, the 2nd reflection part is abbreviate | omitted in the figure.
The spheroidal curved surface has two focal positions, one is set as the light emitting surface position of the LED 29, and the other focal position (second focal point) can be arbitrarily set according to the shape of the first reflecting portion 41. Here, when the second focal point is set to the upper front side of the desk top surface (a), the reflected light from the LED 29 is once focused at the second focal point and spread between the second focal point and the desk top surface. On the desk surface, illumination light can be obtained over a wide range. When the second focal point is made coincident with the desk surface (b), a narrow range can be illuminated with high intensity. Furthermore, when the second focal point is set below the desk surface (c), illumination light is obtained in a state close to parallel light, and illumination light having directivity similar to that of a paraboloid is obtained.

  Therefore, a desired illuminance pattern can be easily obtained by properly using each spheroid curved surface and paraboloid having these illuminance distributions according to the purpose of use. Further, as described above, the reflection surface of the first reflection portion 41 may be configured to be mixedly arranged in addition to the shape of either the spheroidal curved surface or the paraboloid. Furthermore, a configuration may be adopted in which a plurality of spheroidal curved surfaces having different second focus positions are arranged in a mixed manner. For example, it is possible to adjust the degree of light diffusion as a whole desk lighting device by arranging the second focal position on the upper front side of the desk surface and the one on the desk surface in an appropriate ratio. It becomes possible. As a mixed arrangement method, the reflection surfaces of the adjacent first reflection portions 41 can be set to different types, or can be set to different types for each column. It can also be arranged at random. This makes it possible to easily form a desired illuminance distribution in which light collecting properties and light diffusing properties are appropriately combined.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on June 12, 2007 (Japanese Patent Application No. 2007-155464), the contents of which are incorporated herein by reference.

Claims (13)

A desk lamp that has a base installed on the desk surface, a column erected on the base, and a movable support unit that is connected to the column and supports the head movably at the tip, and illuminates the desk surface A device,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
Desk lighting device with A desk lighting device that is provided on the bottom surface of a desk shelf provided at the rear of the desk top surface and illuminates the desk top surface,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
Desk lighting device with A suspended desktop lighting device that is suspended on a ceiling surface directly above the desk surface and illuminates the desk surface,
An array light source in which a plurality of light emitting diodes are arranged in a line of at least one row;
A first reflecting portion having a curved shape provided on the light emitting side of the array light source corresponding to each of the plurality of light emitting diodes and expanding toward the desk surface;
A flat reflecting surface provided along the column direction of the light emitting diodes on the light emitting side of the first reflecting portion and reflecting the light from the light emitting diodes toward the light emitting side is orthogonal to the column direction. A second reflector disposed only on one side of the direction;
A hanging type desktop lighting device with The desk lamp according to any one of claims 1 to 3,
The desk-top illuminating device in which the said 1st reflection part contains the reflective surface which consists of a paraboloid. The desk lamp according to any one of claims 1 to 3,
The desk lighting device in which the first reflection unit includes a reflection surface formed of a spheroid surface. The desk lamp according to any one of claims 1 to 3,
The desk-top lighting device in which the first reflecting section includes a reflecting surface made of a paraboloid and a reflecting surface made of a spheroid. The desk-top lighting device according to any one of claims 1 to 6,
A table-top lighting device in which the light emitting diodes of the arrayed light source are arranged in a plurality of rows and the arrangement intervals of the light emitting diodes are shifted by a half cycle for each row. The desk lamp according to any one of claims 1 to 7,
A desk lighting device in which a satin finish is applied to a reflecting surface of at least one of the first reflecting portion and the second reflecting portion. A desk lighting device according to any one of claims 1 to 8,
A desk lighting device in which the first reflecting portion and the second reflecting portion are integrally formed. A desk lighting device according to any one of claims 1 to 8,
The second reflecting portion is a plate-like elastic body including the flat reflecting surface and a base having a U-shaped cross section connected to the reflecting surface.
The first illumination unit and the array-shaped light source are inserted into a base of the plate-like elastic body, and are held in the base by the elastic restoring force of the plate-like elastic body. A desk lighting device according to claim 10,
The flat reflecting surface of the second reflecting portion is a desk lighting device formed with a white painted surface. A desk lighting device according to claim 10 or 11,
The array light source has a substrate on which a plurality of light-emitting diodes are mounted on the front surface side, and the back surface of the substrate is surface-bonded to the plate-like elastic body via a low heat resistance layer for heat dissipation. A desk lighting device according to claim 12,
A desk lighting device in which the low heat resistance layer for heat dissipation is a thermosetting silicone layer.

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