Abstract:
An LED module (MJ) wherein among apertures ( 21 A to  21 C) and pins ( 11 A to  11 C) to engage each other, the apertures ( 21 A to  21 C) are formed in a mounting board ( 20 ) and the pins ( 11 A to  11 C) are formed on a lens ( 10 ). The apertures ( 21 A to  21 C) and the pins ( 11 A to  11 C) regulate the directivity direction of the lens ( 10 ) to a specific direction by engaging each other in one kind of manner.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a light-emitting module that includes a light source like a light-emitting element, an illumination device that employs the light-emitting module, a display device that incorporates the illumination device, and further a television receiver that incorporates the display device. 
       BACKGROUND ART 
       [0002]    In a liquid crystal display device (display device) that incorporates a non-light-emitting liquid crystal display panel (display panel), usually, also a backlight unit (illumination device), which supplies light to the liquid crystal display panel, is incorporated. There are various kinds of light sources for the backlight unit. For example, in a case of the backlight unit disclosed in a patent document 1, the light source is an LED (Light Emitting Diode). 
         [0003]    In this backlight unit, as shown in  FIG. 20 , a lens  110 , which diffuses light from an LED mounted on a mounting substrate  120 , is disposed (here, a module, which includes the LED, the lens  110  and the mounting substrate  120 , is called a light-emitting module mj). 
       CITATION LIST 
     Patent Literature 
       [0004]    PLT1: JP-A-2000-148332 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    In the meantime, if an illuminance distribution is imaged from the front of the LED module mj by means of an imaging camera, an image as shown in  FIG. 21  is obtained (here, in this imaging, a diffusion plate is interposed between the imaging camera and the lens  110  and the diffusion plate is imaged.) 
         [0006]    This image includes: a rectangular region (dotted-line region) at a central portion; regions (one-dot-one-bar line regions) at four corners; and other regions. Here, the region enclosed by the dotted line is indicated by ar 1 , the region enclosed by the one-dot-one-bar line is indicated by ar 3 , and the other regions are indicated by ar 2 . And, if illuminances (lumen) of these regions ar 1 , ar 2 , and ar 3  are indicated by lm 1 , lm 2 , and lm 3 , respectively, they are in a relationship of lm 1 &gt;lm 2 &gt;lm 3 . 
         [0007]    According to this, it is understood from this image that surface light generated by the LED module mj contains light-amount unevenness. As a way of eliminating the light-amount unevenness, there is a way of mounting, on the mounting substrate  120 , a plurality of kinds of lenses  110  having different lens-surface shapes. 
         [0008]    For example, a lens corresponding to the region ar 1 , a lens for guiding light to the region ar 2 , a lens for guiding light to the region ar 3 , that is, a plurality of kinds of lenses  110  having different directivities of transmitted light are preferably mounted on the mounting substrate  120 . A reason for this is that according to this LED module mj, it is possible to set the directivity direction of the transmitted light to face the regions ar 2  and ar 3  that are likely to become dark areas and to eliminate the dark areas. 
         [0009]    However, in this LED module mj, the number of kinds of the lens  110  increases, which causes the production cost to increase. Besides, for every kind of the lens  110 , a mount position is decided on the mounting substrate  120 ; accordingly, a long time is required to identify the mount position and the production time of the LED module mj cannot avoid becoming long (in short, the positioning of the lens  110  is onerous). 
         [0010]    The present invention has been made to solve the above problems. And, it is an object of the present invention to provide a light-emitting module and the like that curb increase in lens kind and achieve reduction in production burden. 
       Solution to Problem 
       [0011]    The light-emitting module includes: a light-emitting element; a mounting substrate on which the light-emitting element is mounted; and a lens that receives light from the light-emitting element and outputs the light. And, there is a case where in the light-emitting module, the lens outputs part of the light in an directivity direction that is a deflected direction. In such a case, in the light-emitting module, of a first type of restriction portion and a second type of restriction portion that engage with each other, one type is formed through the mount base portion and the other type is formed on the lens; and both types of the restriction portions, by engaging with each other in one way of engagement, restrict the directivity direction of the lens to a specific direction. 
         [0012]    According to this, the directivity direction (e.g., the direction of the lens) of the lens is restricted by the first type of restriction portion and the second type of restriction portion that engage with each other in only one way of engagement; accordingly, the positioning of the lens becomes easy. In other words, the production of the light-emitting module becomes easy. 
         [0013]    In addition, the direction of the lens is decided in advance by the first type of restriction portion and the second type of restriction portion; accordingly, even if the shape of a lens surface of the lens is not variously changed, the illuminance distribution (and the brightness distribution) of the light from the light-emitting module changes variously. Accordingly, for example, even only one kind of lenses are able to variously change the illuminance distribution of the light from the light-emitting module. In other words, the light-emitting module that is easy to produce is achieved while reducing the production cost by curbing the lens cost. 
         [0014]    Here, it is desirable that the first type of restriction portion and the second type of restriction portion have shapes that are fittable in each other. A reason for this is that according to such first type of restriction portion and second type of restriction portion, the structure is simple. 
         [0015]    Besides, instead of the one type of restriction portion formed through the mounting substrate, another member mounted on the mounting substrate may engage with the other type of restriction portion to function as the one restriction portion. A reason for this is that because compared with forming the restriction portion through the mounting substrate, using another member is sometimes able to curb the cost of the light-emitting module. 
         [0016]    Here, the number of the first type of restriction portions and the number of the second type restriction portions may be the same as each other and a single, or may the same as each other and more than one. According to this, in accordance with the cost of both types of restriction portions, the degree of freedom of designing the light-emitting module increases. 
         [0017]    Besides, when a plurality of kinds of the lenses that have directivity direction s different from each other are used; it is desirable that for different kinds of lenses, different kinds of one type of restriction portions are formed, and in accordance with the different kinds, different kinds of the other type of restriction portions as well are formed. 
         [0018]    According to this, on the mounting substrate, mis-positioning of the different kinds of lenses is solved. 
         [0019]    Besides, when the same kind of lenses that have the same directivity direction s as each other are used; it is desirable that the kinds of the one type of restriction portions formed on all the lenses are single, and in accordance with the single kind, the kinds of the other type of restriction portions also are single. 
         [0020]    A reason for this is that according to this, only one kind of lenses are incorporated in the light-emitting module; accordingly, the cost of the light-emitting module is surely curbed. 
         [0021]    Here, an illumination device, which includes the above-described light-emitting module, also is sayable to be the present invention; and a display device, which includes the illumination device and a display panel (e.g., a liquid crystal display panel) that receives light from the illumination device, also is sayable to be the present invention (here, as a device that incorporates the display device, there is a television receiver as an example.). 
       Advantageous Effects of Invention 
       [0022]    According to the light-emitting module of the present invention, the direction of the lens is decided in advance by the first type of restriction portion and the second type of restriction portion; accordingly, even if the shape of a lens surface of the lens is not made to be variously different, the illuminance distribution of the light from the light-emitting module is changed variously; and further, the production is easy. Because of this, the cost of the lens is curbed and the cost of the light-emitting module also is curbed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]      FIG. 1  is a partial perspective view of an LED module (example 1) shown in  FIG. 18 . 
           [0024]      FIG. 2A  is a front view of the LED module according to the example 1. 
           [0025]      FIG. 2B  is a sectional view of the LED module according the example 1 (here, the sectional direction of the sectional view is an A 1 -A 1 ′ arrow direction in  FIG. 1  and  FIG. 2A .). 
           [0026]      FIG. 2C  is a rear view of the LED module according to the example 1. 
           [0027]      FIG. 3A  is a front view of a lens of the LED module according to the example 1. 
           [0028]      FIG. 3B  is a sectional view of the lens of the LED module according the example 1 (here, the sectional direction of the sectional view is a B  1 -B 1 ′ arrow direction in  FIG. 3A .). 
           [0029]      FIG. 3C  is a rear view of the lens of the LED module according to the example 1. 
           [0030]      FIG. 4A  is a front view of a mounting substrate of the LED module according to the example 1. 
           [0031]      FIG. 4B  is a sectional view of the mounting substrate of the LED module according to the example 1 (here, the sectional direction of the sectional view is a C 1 -C 1 ′ arrow direction in  FIG. 4A .). 
           [0032]      FIG. 5  is a plan view when viewing, from front, lenses that are arranged two-dimensionally. 
           [0033]      FIG. 6  is a plan view showing holes and LEDs disposed on a mounting substrate. 
           [0034]      FIG. 7A  is a front view of an egg-shaped lens. 
           [0035]      FIG. 7B  is a sectional view of an egg-shaped lens (here, the sectional direction of the sectional view is a D-D′ arrow direction in  FIG. 7A .) 
           [0036]      FIG. 7C  is a rear view of an egg-shaped lens. 
           [0037]      FIG. 8A  is a plan view showing a desired disposition of egg-shaped lenses. 
           [0038]      FIG. 8B  is a plan view showing an example of a disposition of holes required to achieve the lens disposition of the egg-shaped lenses shown in  FIG. 8A . 
           [0039]      FIG. 9A  is a plan view showing a desired disposition of egg-shaped lenses different from  FIG. 8A . 
           [0040]      FIG. 9B  is a plan view showing an example of a disposition of holes required to achieve the lens disposition shown in  FIG. 9A . 
           [0041]      FIG. 10A  is a front view of an LED module according to an example 2. 
           [0042]      FIG. 10B  is a sectional view of the LED module according the example 2 (here, the sectional direction of the sectional view is an A 2 -A 2 ′ arrow direction in  FIG. 10A .). 
           [0043]      FIG. 10C  is a rear view of the LED module according to the example 2. 
           [0044]      FIG. 11A  is a front view of a lens of the LED module according to the example 2. 
           [0045]      FIG. 11B  is a sectional view of the lens of the LED module according the example 2 (here, the sectional direction of the sectional view is a B 2 -B 2 ′ arrow direction in  FIG. 11A .). 
           [0046]      FIG. 11C  is a rear view of the lens of the LED module according to the example 2. 
           [0047]      FIG. 12A  is a front view of a mounting substrate of the LED module according to the example 2. 
           [0048]      FIG. 12B  is a sectional view of the mounting substrate of the LED module according to the example 2 (here, the sectional direction of the sectional view is a C 2 -C 2 ′ arrow direction in  FIG. 12A .). 
           [0049]      FIG. 13A  is a front view of an LED module according to an example 3. 
           [0050]      FIG. 13B  is a sectional view of the LED module according the example 3 (here, the sectional direction of the sectional view is an A 3 -A 3 ′ arrow direction in  FIG. 13A .). 
           [0051]      FIG. 13C  is a rear view of the LED module according to the example 3. 
           [0052]      FIG. 14A  is a front view of an LED module according to an example 4. 
           [0053]      FIG. 14B  is a sectional view of the LED module according the example 4 (here, the sectional direction of the sectional view is an A 4 -A 4 ′ arrow direction in  FIG. 14A .). 
           [0054]      FIG. 14C  is a rear view of the LED module according to the example 4. 
           [0055]      FIG. 15A  is a front view of a lens of the LED module according to the example 4. 
           [0056]      FIG. 15B  is a sectional view of the lens of the LED module according the example 4 (here, the sectional direction of the sectional view is a B 4 -B 4 ′ arrow direction in  FIG. 15A .). 
           [0057]      FIG. 15C  is a rear view of the lens of the LED module according to the example 4. 
           [0058]      FIG. 16A  is a front view of a mounting substrate of the LED module according to the example 4. 
           [0059]      FIG. 16B  is a sectional view of the mounting substrate of the LED module according to the example 4 (here, the sectional direction of the sectional view is a C 4 -C 4 ′ arrow direction in  FIG. 16A .). 
           [0060]      FIG. 17A  is a front view of an LED module according to an example 5. 
           [0061]      FIG. 17B  is a sectional view of the LED module according the example 5 (here, the sectional direction of the sectional view is an A 5 -A 5 ′ arrow direction in  FIG. 17A .). 
           [0062]      FIG. 17C  is a rear view of the LED module according to the example 5. 
           [0063]      FIG. 18  is an exploded perspective view of a liquid crystal display device. 
           [0064]      FIG. 19  is an exploded perspective view of a liquid crystal television that incorporates a liquid crystal display device. 
           [0065]      FIG. 20  is a perspective view of a conventional LED module. 
           [0066]      FIG. 21  is an image showing an illumination distribution of surface light from the LED module in  FIG. 20 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1  
       [0067]    An embodiment 1 is described based on drawings as follows. Here, for convenience, there is a case where a hatching, a member reference number and the like are omitted; in such a case, other drawings are referred to. Besides, for convenience, a hatching is also sometimes applied to a view other than a sectional view. 
         [0068]      FIG. 19  shows a liquid crystal television  89  that incorporates a liquid crystal display device (display device). Here, this liquid crystal television  89  receives a television broadcast signal to display an image, accordingly, it is sayable to be a television receiver.  FIG. 18  is an exploded perspective view showing the liquid crystal display device. As shown in this figure, the liquid crystal display device  69  includes: a liquid crystal display panel  59 ; a backlight unit (illumination device)  49  that supplies light to the liquid crystal display panel  59 ; and a housing HG (front housing HG 1 , rear housing HG 2 ) that sandwiches these members. 
         [0069]    The liquid crystal display panel  59  attaches an active matrix substrate  51  that includes switching elements such as a TFT (Thin Film Transistor) and the like, and an opposite substrate  52  that faces the active matrix substrate  51  to each other by means of a seal member (not shown). And, liquid crystal (not shown) is injected into a gap between both substrates  51 ,  52 . 
         [0070]    Here, a light polarization film  53  is mounted on a light reception surface of the active matrix substrate  51  and on an output surface of the opposite substrate  52 . And, the liquid crystal display panel  59  displays an image by using a change in transmittance due to inclination of liquid crystal molecules. 
         [0071]    Next, the backlight unit  49 , which is situated right under the liquid crystal display panel  59 , is described. The backlight unit  49  includes: an LED module (light-emitting module) MJ; a backlight chassis  41 ; a large reflection sheet  42 ; a diffusion plate  43 ; a prism sheet  44 ; and a micro-lens sheet  45 . 
         [0072]    The LED module MJ, as shown in  FIG. 1  that is a partial perspective view of  FIG. 18 , includes: a mounting substrate  20 ; an LED (Light Emitting Diode)  31 ; and a lens  10 . 
         [0073]    The mounting substrate  20  is a plate-shaped and rectangular substrate and a plurality of electrodes (not shown) are arranged on a mount surface  20 U. And, LEDs  31 , which are light-emitting elements, are mounted on these electrodes. Here, a resist film (not shown), which serves as a protection film, is formed on the mount surface  20 U of the mounting substrate  20 . This resist film is not especially limited, however, is desirable to be white that has a reflection characteristic. A reason for this is that even if light enters the resist film, the light reflects off the resist film to travel to outside; accordingly, light absorption by the mounting substrate  20 , that is, a cause of light-amount unevenness is solved. 
         [0074]    The LED  31  is a light source and emits light by means of an electric current transmitted via the electrode of the mounting substrate  20 . And, there are many kinds of the LEDs  31  and the following is an example of the LED  31 . For example, there is the LED  31  that includes: an LED chip (light-emitting chip) that emits blue light and a fluorescent body that receives light from the LED chip to emit yellow fluorescent light (here, the LED chip is not especially limited in number). The LED  31  generates white light by means of the light from the blue-light emitting LED chip and the light due to the fluorescent light emission. 
         [0075]    However, the fluorescent body incorporated in the LED  31  is not limited to the fluorescent body that emits the yellow fluorescent light. For example, the LED  31  may include: the blue-light emitting LED chip; and fluorescent bodies that receive the light from the LED chip to emit green fluorescent light and red fluorescent light, respectively and may generate white light by means of the blue light from the LED chip and the light (green light and red light) due to the fluorescent light emission. 
         [0076]    Besides, the LED chip incorporated in the LED  31  is not limited to the chip that emits the blue light. For example, the LED  31  may include: a red-light emitting red LED chip; a blue-light emitting blue LED chip; and a fluorescent body that receive the light from the blue LED chip to emit green fluorescent light. A reason for this is that such LED  31  is able to generate white light by means of the red light from the red LED chip, the blue light from the blue LED chip and the green light due to the fluorescent light emission. 
         [0077]    Besides, the LED  31  may not include any fluorescent body. For example, the LED  31  may include: a red-light emitting red LED chip; a green-light emitting green LED chip; and a blue-light emitting blue LED chip; and generate white light by means of the light from all the LED chips. 
         [0078]    Besides, in the backlight unit  49  shown in  FIG. 18 , one mounting substrate  20  includes: a relatively short mounting substrate  20  on which five LEDs  31  are mounted in a line; and a relatively long mounting substrate  20  on which eight LEDs  31  are mounted in a line. 
         [0079]    Especially, the two kinds of mounting substrates  20  are so arranged as to form a line of thirteen LEDs  31  that is composed of the line of five LEDs  31  and the line of eight LEDs  31 ; further, the two kinds of mounting substrates  20  are also arranged in a direction that intersects (e.g, meets at right angles) the direction in which the thirteen LEDs  31  are arranged. According to this, the LEDs  31  are disposed into a matrix shape and emit surface light (for convenience, the direction in which the different mounting substrates  20  are arranged is defined as an X direction, the direction in which the same kinds of mounting substrates  20  are arranged is defined as a Y direction, and the direction that intersects the X direction and the Y direction is defined as a Z direction.) 
         [0080]    Here, the thirteen LEDs  31  arranged in the X direction are electrically connected in series to each other; and the thirteen LEDs  31  connected in series are electrically connected in parallel with other thirteen LEDs  31  that are adjacent along the Y direction and electrically connected in series to each other. And, the LEDs  31  arranged in the matrix shape are parallel-driven. 
         [0081]    The lens  10  receives the light from the LED  31  and transmits (outputs) the light. In detail, the lens  10  has a housing concave DH (see  FIG. 3B  described later), which is able to house the LED  31 , on a rear surface  10 B (light reception surface) opposite to a lens surface  10 S; the housing concave DH is positioned with respect to the LED  31  to cover the LED  31 . According to this, the LED  31  is buried in an inside of the lens  10  and the light from the LED  31  is surely supplied to the inside of the lens  10 . And, most of the supplied light exits to outside via the lens surface  10 S (incidentally, a way of mounting the lens  10  onto the mounting substrate  20  is described later). 
         [0082]    Here, a material of the lens  10  is not especially limited; for example, there is an acrylic resin (there is an acrylic resin that has a refractive index nd of 1.49 to 1.50). 
         [0083]    The backlight chassis  41 , as shown in  FIG. 18 , is a box-shaped member, for example, and the LED modules MJ are densely disposed on a bottom surface  41 B, whereby the plurality of LED modules MJ are housed. Here, the bottom surface  41 B of the backlight chassis  41  and the mounting substrate  20  of the LED module MJ are connected to each other via a rivet  33  (see  FIG. 17A  to  FIG. 17C  described later), for example. 
         [0084]    Besides, the bottom surface  41 B of the backlight chassis  41  may be provided with a support pin that supports the diffusion plate  43 , the prism sheet  44 , and the micro-lens sheet  45  (here, the backlight chassis  41 , together with the support pin, may stack up and support the diffusion plate  43 , the prism sheet  44 , and the micro-lens sheet  45  in this order by means of the top of a side wall.). 
         [0085]    The large reflection sheet  42  is an optical sheet that has a reflection surface  42 U and covers the plurality of LED modules MJ disposed in the matrix shape with a rear surface of the reflection surface  42 U faced with the plurality of LED modules MJ. However, the large reflection sheet  42  is provided with a through-hole  42 H aligned with the position of the lens  10  of the LED module MJ, thereby exposing the lens  10  via the reflection surface  42 U (here, holes for exposing the above rivet  33  and the support pin may be formed.). 
         [0086]    According to this, even if part of the light output from the lens  10  travels toward the bottom surface  41 B of the backlight chassis  41 , the light reflects off the reflection surface  42 U of the large reflection sheet  42  and travels to go away from the bottom surface  41 B. Accordingly, thanks to the presence of the large reflection sheet  42 , the light from the LED  31  is not lost and travels to the diffusion plate  43  opposite to the reflection surface  42 U. 
         [0087]    The diffusion plate  43  is an optical sheet that overlies the large reflection sheet  42 , and diffuses the light emitted from the LED module MJ and the reflected light from the large reflection sheet  42 U. In other words, the diffusion plate  43  diffuses the surface light formed by the plurality of LED modules MJ to spread the light throughout the liquid crystal display panel  59 . 
         [0088]    The prism sheet  44  is an optical sheet that overlies the diffusion plate  43 . And, on the prism sheet  44 , triangular prisms each extending in a direction (linear) are arranged on the sheet surface in a direction that intersects the linear direction. According to this, the prism sheet  44  deflects a radiation characteristic of the light from the diffusion plate  44 . Here, the prisms preferably extend along the Y direction in which the small number of LEDs  31  are disposed and are arranged along the X direction in which the large number of LEDs  31  are disposed. 
         [0089]    The micro-lens sheet  45  is an optical sheet that overlies the prism sheet  44 . And, in the inside of the micro-lens sheet  45 , micro-particles for refracting and scattering the light are dispersed. According to this, the micro-lens sheet  45  does not locally concentrate the light from the prism sheet  44 , thereby curbing brightness difference (light-amount unevenness). 
         [0090]    And, the above-described backlight unit  49  transmits the surface light formed by the plurality of LED modules MJ through the plurality of optical sheets  43  to  45  and supplies the light to the liquid crystal display panel  59 . According to this, the non-light emitting liquid crystal display panel  59  receives the light (backlight) from the backlight unit  49  to increase a display function. 
         [0091]    Here, a way of disposing and mounting the lens  10  of the LED module MJ is described using  FIG. 1  to  FIG. 6 .  FIG. 5  is a plan view when viewing the lenses  10  that are arranged two-dimensionally; and  FIG. 6  is a plan view that shows the LED  31  and holes  21 A to  21 C formed in or through the mounting substrate  20  to mount the lens  10  (here, in  FIG. 6 , for convenience, the outer shape of the lens  10  is shown by a one-dot-one-bar line.). 
         [0092]    Besides,  FIG. 1  is a partial perspective view of the LED module MJ;  FIG. 2A  to  FIG. 2C  are a front view, a sectional view, and a rear view of the LED module MJ, respectively (here, the sectional direction of the sectional view is an A 1 -A 1 ′ arrow direction in  FIG. 1  and  FIG. 2A .).  FIG. 3A  to  FIG. 3C  are a front view, a sectional view, and a rear view of the lens  10 , respectively (here, the sectional direction of the sectional view is a B 1 -B 1 ′ arrow direction in  FIG. 3A .);  FIG. 4A  and  FIG. 4B  are a front view, and a sectional view of the mounting substrate, respectively (here, the sectional direction of the sectional view is a C 1 -C 1 ′ arrow direction in  FIG. 4A .). Here, the LED module MJ shown in  FIG. 1  and others is called an example 1 (EX1). 
         [0093]    First, a shape of the lens  10  is described. As shown in  FIG. 2A  to  FIG. 2C  and others, the lens  10  includes: the rear surface  10 B that is provided with the housing concave DH for housing the LED  31 ; and the curved lens surface  10 S that is situated oppositely to the rear surface  10 B and outputs the light emitted from the LED  31 . Especially, when viewing from the front (in detail, when viewing, from the front, an XY plane defined by the X direction and the Y direction), the lens  10  includes the lens surface  10 S that has an ellipse shape (in other words, the circumferential shape of the foot of the lens surface  10 S is the elliptic.). 
         [0094]    In a case where the lens  10 , which includes such elliptic circumferential shape and the curved lens surface  10 S, transmits the light, the light is diffused, but most of the light is deflected in a direction (directivity direction) along a minor-axis direction of the elliptic shape. And, as shown in  FIG. 5  and  FIG. 6 , in the LED module MJ, the lens  10  is disposed such that a major-axis direction of the lens  10  is along a radiation direction. In other words, the plurality of lenses  10  are radially arranged with respect to a point near a center of the bottom surface  41 B of the backlight chassis  41 . 
         [0095]    According to this, the directions of the light output from the respective lenses  10  are variously different. Because of this, even if the lenses  10  are disposed in the matrix shape, light-amount unevenness having an interference pattern (e.g, a lattice shape) due to the disposition does not appear. Besides, the lens  10  spreads, by means of the direction of itself, the transmitted light into the corners of the backlight chassis  41  which often becomes relatively dark. 
         [0096]    For example, the corners of the backlight chassis  41  are preferably situated in the directions in which the lens  10  deflects most of the light. And, according to this, the light spreads into the corner of the liquid crystal display panel  59  that overlies the bottom surface  41 B of the backlight chassis  41  as well, whereby light-amount unevenness becomes unlikely to occur on the liquid crystal display panel  59 . 
         [0097]    In the meantime, as described above, in the case where the transmitted light from the lens  10  has directivity, the direction in which to mount the lens  10  onto the mounting substrate  20  becomes important. Because of this, first, a way of mounting the lens  10  (in other words, a connection mechanism for the lens  10  and the mounting substrate  20 ) is described. 
         [0098]    As shown in  FIG. 3A  to  FIG. 3C , the lens  10  includes: the rear surface  10 B which is provided with the housing concave DH for housing the LED  31 ; and the curved lens surface  10 S that is situated oppositely to the rear surface  10 B and outputs the light emitted from the LED  31 . Further, the lens  10  includes pins  11  as well ( 11 A to  11 C; first restriction portion/second restriction portion) that protrude from the rear surface  10 B. These pins  11 A to  11 C engage with holes  21  ( 21 A to  21 C; second restriction portion/first restriction portion) that are formed in or through the mounting substrate  20  as shown in  FIG. 4A  and  FIG. 4B , whereby the lens  10  is mounted onto the mounting substrate  20 . 
         [0099]    In detail, the pins  11 A,  11 B are so formed as to interpose the housing concave DH on the rear surface  10 B of the lens  10 . Specifically, the pin  11 A is situated on one end side in the major-axis direction of the elliptic shape, while the pin  11 B is situated on the other end side in the major-axis direction of the elliptic shape (here, the pin  11 A and the pin  11 B are in a symmetrical relationship with respect to a point.). These pins  11 A,  11 B include: a quadrangular pole-shaped shank portion  12  ( 12 A, 12 B) that extends to go away from the rear surface  10 B of the lens  10 ; and a flexible engagement piece  13  ( 13 A,  13 B) that is formed near a tip of the shank portion  12  (here, the engagement piece  13  is a flexible piece member that protrudes from a side wall of the shank portion  12  near the tip of the shank portion  12 .). 
         [0100]    On the other hand, as shown in  FIG. 4A  and  FIG. 4B , the mounting substrate  20  is provided with the holes  21 A and  21 B that have a shape similar to and slightly larger than the shape of the shank circumference (quadrangular shank circumference) of the shank portions  12 A and  12 B of the pins  11 A and  11 B such that the holes  21 A and  21 B interpose the LED  31 . And, the pins  11 A,  11 B are inserted into the holes  21 A, and  21 B, respectively. The shank portions  12 A,  12 B of the pins  11 A,  11 B are slightly longer than the thickness of the mounting substrate  20  and the holes  21 A,  21 B penetrate the mounting substrate  20 . Because of this, when the pins  11 A,  11 B are inserted into the holes  21 A and  21 B, the tips of the shank portions  12 A,  12 B protrude from the rear surface  20 B opposite to the mount surface  20 U. 
         [0101]    Here, during the process in which the shank portions  12 A,  12 B of the pins  11 A,  11 B go into the holes  21 A and  21 B, the engagement pieces  13 A,  13 B are so pressed and deformed by inner walls of the holes  21 A,  21 B as to fit into the holes  21 A,  21 B. However, when the tips of the shank portions  12 A,  12 B protrude from the rear surface  20 B opposite to the mount surface  20 U, the engagement pieces  13 A,  13 B are not pressed by the inner walls of the holes  21 A,  21 B; accordingly, the engagement pieces  13 A,  13 B restore the original shape. According to this, as shown in  FIG. 2B , the engagement pieces  13 A,  13 B hook onto edges of the holes  21 A and  21 B, whereby the lens  10  is mounted onto the mounting substrate  20 . 
         [0102]    On the other hand, the pin  11 C is formed at a position that is close to the pin  11 A and, for example, closer to an outer edge of the rear surface  10 B of the lens  10  than the pin  11 A is. The pin  11 C is formed of a cylindrical shank portion  12 C only, for example (here, this shank portion  12 C may be shorter than the thickness of the mounting substrate  20 .). 
         [0103]    And, the hole  21 C corresponding to the pin  11 C has a length long enough to accommodate the total length of the shank portion  12 C and is formed near the hole  21 A (here, the hole  21 C is a hole including a shape that is slightly larger than and similar to the shape of the shank circumference (circular shank circumference) of the shank portion  12 C of the pin  11 C.). In detail, the hole  21 C is formed at an end of the mounting substrate  20  that touches the tip of the pin  11 C during the process in which the pins  11 A,  11 B are inserted into the holes  21 A,  21 B. 
         [0104]    According to this, when the pins  11 A,  11 B are inserted into the holes  21 A and  21 B; the engagement pieces  13 A,  13 B hook onto the edges of the holes  21 A and  21 B; and the lens  10  is mounted onto the mounting substrate  20 , the pin  11 C fits into the hole  21 C as shown in  FIG. 2B . 
         [0105]    The pins  11 A to  11 C and the holes  21 A to  21 C are intended to mount the lens  10  onto the mounting substrate  20  by means of only one way of mounting. For example, in a case where the pin  11 C is not present and only the pins  11 A and  11 B are formed on the rear surface  10 B of the lens  10 , even if the pins  11 A,  11 B are so designed as to fit into the holes  21 A and  21 B, there is a likelihood that the pin  11 A is fitted into the hole  21 B and the pin  11 B is fitted into the hole  21 A. 
         [0106]    However, the pin  11 C is formed on the lens  10  and the hole  21 C, into which the pin  11 C fits, is formed in the mounting substrate  20 ; and the pins  11 A,  11 B are so designed as to fit into the holes  21 A and  21 B; accordingly, the pin  11 A is not fitted into the hole  21 B and the pin  11 B is not fitted into the hole  21 A. In other words, the pin  11 A is fitted into the hole  21 A, the pin  11 B is fitted into the hole  21 B, and the pin  11 C is fitted into the hole  21 C, and are not fitted with any other ways. 
         [0107]    For example, as shown in  FIG. 7A  to  FIG. 7C , in a case where the shape of the lens  10  is an egg shape when viewing from the front, it is desirable that the pin  11 A is fitted into the hole  21 A, the pin  11 B is fitted into the hole  21 B, and the pin  11 C is fitted into the hole  21 C, and are not fitted with any other ways. 
         [0108]    In detail, as shown in  FIG. 8A , in a case where three lenses  10  are radially arranged such that smaller portions of the egg-shaped lenses  10  are away from a center of the radiation, the pins  11 C situated on larger portions of the egg-shaped lenses  10  gather at the center of the radiation. Because of this, as shown in  FIG. 8B , also in the mounting substrate  20 , the holes  21 C in which the pins  11 C fit are formed at the center of the radiation. And, if the three lenses  10  are mounted onto the mounting substrate  20 , a desired disposition of the lenses  10  as shown in  FIG. 8A  is achieved. 
         [0109]    However, as shown in  FIG. 9B , in a case where the mounting substrate  20  is not provided with the hole  21 C and provided with the holes  21 A and  21 B only (naturally, the lens  10  is provided with the pins  11 A and  11 B only), as shown in  FIG. 9A , there is a likelihood that the three lenses  10  are arranged such that the larger portions of the egg-shaped lenses  10  are away from the center of the radiation. 
         [0110]    If the lenses  10  are arranged as shown in  FIG. 9A , the arrangement is the same radial arrangement as that of the lenses  10  in  FIG. 8A , but the directions of the lenses  10  are different. And, if the directions of the lenses  10  are different from each other, the directions in which part of the light from the lens  10  is deflected are different from each other. Accordingly, an illuminance distribution (and a brightness distribution) obtained from the arrangement of the lenses  10  as shown in  FIG. 8A  is not obtained from the arrangement of the lenses  10  as shown in  FIG. 9A . 
         [0111]    In other words, in a case where the lens  10  outputs part of the light in an directivity direction that is an deflected direction, in the LED module MJ, of the holes  21 A to  21 C and the pins  11 A to  11 C that engage with each other, the holes  21 A to  21 C are formed in or through the mounting substrate  20 , while the pins  11 A to  11 C are formed on the lens  10 . And, the holes  21 A to  21 C engage with the pins  11 A to  11 C by means of the only one way of engagement, thereby restricting the direction of the lens  10 , that is, the directivity direction of the lens  10  to a specific direction (here, in optical design, the specific direction is an arbitrary direction in which the output light from the lens  10  is guided.). 
         [0112]    According to this, even if the LED  31  has regularity and is arranged in the matrix shape, by covering the LED  31  with one kind of lens  10 , it is possible to variously change the illuminance distribution of the surface light formed by the plurality of LEDs  31  (e.g., it is possible to increase the illuminance near the center of the surface light and the illuminance of the surface light near the circumference.). A reason for this is that the light is diffused via the lens  10  while having directivity and the directivity direction is set at any direction. 
         [0113]    In addition, the LED module MJ is able to variously change the brightness distribution of the backlight; nevertheless, it is sufficient if there is one kind of lenses  10 . Because of this, the production cost of the lens  10  is curbed and the cost reductions of the LED module MJ, the backlight units  49  and further the liquid crystal display device  69  are achieved. Besides, the directivity direction of the lens  10  (and the direction of the lens  10 ) is restricted by the pin  11  and the hole  21  that engage with each other by means of the only one way of engagement; accordingly, the positioning of the lens  10  becomes easy (in other words, the production burden of the LED module MJ reduces.). 
       Embodiment 2  
       [0114]    An embodiment 2 is described. Here, members having the same functions as members used in the embodiment 1 are indicated by the same reference numbers and description of them is skipped. 
         [0115]    In the LED module MJ according to the example 1 of the embodiment 1, the lens  10  is provided with the three pins  11 A to  11 C. However, the number of pins  11  is not limited to three. Because of this, as an example 2 (EX2), the LED module MJ, which incorporates the lens  10  having two pins  11 , is described using  FIG. 10A  to  FIG. 12B . 
         [0116]      FIG. 10A  to  FIG. 10C  are a front view, a sectional view, and a rear view of the LED module MJ, respectively (here, the sectional direction of the sectional view is an A 2 -A 2 ′ arrow direction in  FIG. 10A .).  FIG. 11A  to  FIG. 11C  are a front view, a sectional view, and a rear view of the lens  10 , respectively (here, the sectional direction of the sectional view is a B 2 -B 2 ′ arrow direction in  FIG. 11A .);  FIG. 12A  and  FIG. 12B  are a front view, and a sectional view of the mounting substrate, respectively (here, the sectional direction of the sectional view is a C 2 -C 2 ′ arrow direction in  FIG. 12A .). 
         [0117]    As shown in  FIG. 11A to 11C , the lens  10  includes the pin  11 A and the pin  11 D on the rear surface  10 B. In detail, the pin  11 A and the pin  11 D are, like the pin  11 A and the pin  11 B in the example 1, so formed as to interpose the housing concave DH (here, the pin  11 A and the pin  11 D are in a symmetrical relationship with respect to a point.). 
         [0118]    The pin  11 A is the same as the pin  11 A of the lens  10  according to the example 1, accordingly, the hole  21 A, which is the same as that in the example 1, is formed through the mounting substrate  20 . On the other hand, the pin  11 D (first restriction portion/second restriction portion) includes a shank portion  12 D that is different from the pin  11 A. In detail, the pin  11 D includes the shank portion  12 D whose shank circumference has a trapezoidal shape. The shank portion  12 D is slightly longer than the thickness of the mounting substrate  20  and includes an engagement piece  13 D at a tip. 
         [0119]    And, a hole  21 D (second restriction portion/first restriction portion) corresponding to the pin  11 D is formed through the mounting substrate  20 . The hole  21 D is a hole including a shape slightly larger than and similar to the shape of the shank circumference of the shank portion  12 D of the pin  11 D; and penetrates the mounting substrate  20 . Because of this, when the pins  11 A,  11 D are inserted into the holes  21 A and  21 D, the tips of the shank portions  12 A and  12 D protrude from the rear surface  20 B opposite to the mount surface  20 U. And, when the tips of the shank portions  12 A,  12 D protrude from the rear surface  20 B opposite to the mount surface  20 U, the engagement pieces  13 A,  13 D hook onto the edges of the holes  21 A,  21 D; and the lens  10  is mounted onto the mounting substrate  20 . 
         [0120]    The pins  11 D and the hole  21 D are intended to mount the lens  10  onto the mounting substrate  20  by means of only one way of mounting. For example, in a case where instead of the pin  11 D, the pin  11 B in the example 1 is formed on the rear surface  10 B of the lens  10 , even if the pins  11 A is so designed as to fit into the hole  21 A and the pin  11 B is so designed as to fit into the holes  21 B, there is a likelihood that the pin  11 A is fitted into the hole  21 B and the pin  11 B is fitted into the hole  21 A. 
         [0121]    However, instead of the pin  11 B, the pin  11 D is formed on the lens  10  and the hole  21 D, into which the pin  11 D fits, is formed through the mounting substrate  20 ; and the pin  11 A is so designed as to fit into the hole  21 A and the pin  11 D is so designed as to fit into the holes  21 D; accordingly, there are no other ways of fitting. 
         [0122]    In other words, of the holes  21 A and  21 D and the pins  11 A and  11 D that engage with each other, the holes  21 A and  21 D are formed through the mounting substrate  20 , while the pins  11 A and  11 D are formed on the lens  10 . And, the holes  21 A and  21 D engage with the pins  11 A and  11 D by means of the only one way of engagement, thereby restricting the direction of the lens  10  (the directivity direction of the lens  10 ) to a specific direction. 
         [0123]    Accordingly, the LED module achieves the same function and effect as the embodiment 1. In other words, in the LED module, the light is diffused via the lens  10  while having directivity and the directivity direction is set arbitrarily. Besides, the LED module MJ is able to variously change the illuminance distribution of the backlight; nevertheless, it is sufficient if there is one kind of lenses  10 . Further, the production burden of the LED module MJ is small. 
         [0124]    Besides, the LED module MJ according to the example 2 allows the number of pins  11  to be reduced compared with the LED module MJ according to the example 1; accordingly, it is possible to further curb the production cost of the lens  10 . Because of this, the cost reductions of the LED module MJ, the backlight unit  49  and further the liquid crystal display device  69  are achieved. 
         [0125]    In the meantime, as shown in  FIG. 13A to 13C , in the LED module MJ according to the example 2, the lens  10  may be provided with the pin  11 D only; and the mounting substrate  20  may be provide with the hole  21 D only (here, such LED module is called an example 3 (EX3).). 
         [0126]    The trapezoidal shape (sectional shape interesting the shank direction) of the shank circumference of the shank portion  12 D of the pin  11 D is a trapezoidal shape that is not symmetrical with respect to a point nor symmetrical with respect a line; and in accordance with the trapezoidal shape, the trapezoidal shape of the hole  21 D also is not symmetrical with respect to a point nor symmetrical with respect to a line (here, three of the four corners have an angle of 90°.). Because of this, the hole  21 D engages with the pin  11 D by means of the only one way of engagement, thereby restricting the directivity direction of the lens  10  to a specific direction. Accordingly, the LED module MJ according to the example 3 achieves the same function and effect as the LED module MJ according the example 2. 
       Embodiment 3  
       [0127]    An embodiment 3 is described. Here, members having the same functions as members used in the embodiments 1 and 2 are indicated by the same reference numbers and description of them is skipped. 
         [0128]    In the example 1 of the embodiment 1 and the examples 2 and 3 of the embodiment 2, the pin  11  restricts the direction of the lens  10  (and the directivity direction of the lens  10 ). However, it is not the pin  11  only that restricts the direction of the lens  10 . Here, the LED module MJ according to an example 4 (EX4), which restricts the direction of the lens  10 , is described using  FIG. 14A  to  FIG. 16B . 
         [0129]      FIG. 14A to 14C  are a front view, a sectional view, and a rear view of the LED module MJ, respectively (here, the sectional direction of the sectional view is an A 4 -A 4 ′ arrow direction in  FIG. 14A .).  FIG. 15A  to  FIG. 15C  are a front view, a sectional view, and a rear view of the lens  10 , respectively (here, the sectional direction of the sectional view is a B 4 -B 4  arrow direction in  FIG. 15A .);  FIG. 16A  and  FIG. 16B  are a front view, and a sectional view of the mounting substrate, respectively (here, the sectional direction of the sectional view is a C 4 -C 4 ′ arrow direction in  FIG. 16A .). 
         [0130]    As shown in  FIG. 15A  to  FIG. 15C , the lens  10 , like in the example 1, includes the housing concave DH, the pin  11 A and the pin  11 B to interpose the housing concave DH on the rear surface  10 B. Further, in the lens  10 , an edge of the rear surface  10 B on the pin  11 A side is so recessed from the rear surface  10 B as to from a step  16  (here, on the rear surface  10 B, the step  16  includes: a step lower portion  16 L recessed from the rear surface  10 B; and a step upper portion  16 H that is the rear surface  10 B portion other than the step lower portion  16 L.). 
         [0131]    On the other hand, as shown in  FIG. 16A and 16B , the mounting substrate  20  is provided with the holes  21 A and  21 B into which the pins  11 A and  11 B of the lens  10  fit, respectively. Further, a partial region of the mount surface  20 U surrounding the holes  21 A and  21 B is so recessed from the rest of the mount surface  20 U as to form a recessed portion  26 . 
         [0132]    The shape of the recessed portion  26 , that is, the circumferential shape of the recessed portion  26  of the mount surface  20 U is a shape that is slightly larger than and similar to the shape of the step upper portion  16 H (first restriction portion/second restriction portion) of the rear surface  10 B of the lens  10 . Especially, when the holes  21 A and  21 B fit into the pins  11 A and  11 B, the recessed portion  26  (second restriction portion/first restriction portion) is substantially aligned with and overlies the step upper portion  16 H of the rear surface  10 B of the lens  10 . Besides, the depth of the recessed portion  26  is substantially the same as the length (in other words, the length of the step  16 ) that is a height difference between the step upper portion  16 H of the rear surface  10 B of the lens  10  and the step lower portion  16 L. 
         [0133]    Here, the holes  21 A,  21 B have a total length shorter than the holes  21 A,  21 B in the example 1. A reason for this is that the holes  21 A,  21 B in the example 4 are formed under the recessed portion  26  that is the concave of the mount surface  20 U. Besides, in accordance with the lengths of the holes  21 A,  21 B in the example 4, also the lengths of the pins  11 A,  11 B of the lens  10  are shorter than the lengths of the pins  11 A,  11 B in the example 1 (of course, the pins  11 A,  11 B have a length that allows the tips of the shank portions  12 A,  12 B to protrude from the rear surface  20 B opposite to the mount surface  20 U.). 
         [0134]    As described above, the mounting substrate  20  is provided with the recessed portion  26  and the holes  21 A,  21 B that are situated through the recessed portion  26 ; accordingly, during the process in which the pins  11 A,  11 B of the lens  10  are inserted into the holes  21 A and  21 B, the rear surface  10 B of the lens  10  gradually nears the recessed portion  26  and fits into the recessed portion  26 . 
         [0135]    Because of this, when the pins  11 A,  11 B are inserted into the holes  21 A,  21 B; the engagement pieces  13 A,  13 B hook onto the edges of the holes  21 A,  21 B; and the lens  10  is mounted onto the mounting substrate  20 , as shown in  FIG. 14B , the step upper portion  16 H of the rear surface  10 B of the lens  10  rests on the recessed portion of the mounting substrate  20 . 
         [0136]    In other words, of the step upper portion  16 H (which is sayable to be a foot portion of the lens  10 ) of the lens  10  and the recessed portion  26  that engage with each other, the recessed portion  26  is formed on the mounting substrate  20 , while the step upper portion  16 H, which is non-rotation symmetrical and non-point symmetrical thanks to the step  16 , is formed on the lens  10 . And, the recessed portion  26  and the step upper portion  16 H engage with each other by means of the only one way of engagement, thereby restricting the direction (that is, the directivity direction of the lens  10 ) of the lens  10  to a specific direction. Accordingly, the LED module MJ according to the example 4 achieves the same function and effect as the LED modules MJ according the examples 2, 3. 
         [0137]    Here, the step  16  of the lens  10  of the LED module MJ according to the example 4 is aligned with a linear edge of the recessed portion  26 ; further, a circumferential edge of the step upper portion  16 H of the lens  10  is aligned with a curved edge of the recessed portion  26 . In other words, thanks to the contact between part of the lens  10  and part of the mounting substrate  20 , the direction of the lens  10  is restricted. 
         [0138]    However, for the positioning of the lens  10 , it is not the mounting substrate  20  only that comes into contact with the lens  10 . For example, as shown in  FIG. 17A  to  FIG. 17C , the rivet  33  for mounting the mounting substrate  20  onto the backlight chassis  41  sometimes functions as the positioning member for the lens  10  (here, such LED module MJ is called an example 5.). 
         [0139]    In detail, in the LED module MJ according to the example 5 (EX5), as shown in  FIG. 17A  to  FIG. 17C , the rivet  33 , which includes a head  33 T formed of a rectangular-shaped plate member and a shank  33 A formed of a quadrangular-shaped pole, is inserted from the mount surface  20 U of the mounting substrate  20 , whereby the mounting substrate  20  and the bottom surface  41 B of the backlight chassis  41  are connected to each other (here, in  FIG. 17A  to  FIG. 17C , the backlight chassis  41  is omitted for convenience.). 
         [0140]    And, a flat surface of the step  16  of the lesn  10  and a flat surface of the step lower portion  16 L are aligned with linear edges of the head  33 T of the rivet  33  (here, the step  16  and the step lower portion  16 L may be collectively called a step portion  17  (first restriction portion/second restriction portion.)). In other words, instead of the hole  21  formed in the mounting substrate  20 , the head  33 T, which is part of the rivet (another member)  33  mounted on the mounting substrate  20 , engages with the step portion  17  of the lens  10  and performs the same function as the hole  21 . 
         [0141]    Because of this, the linear edge of the head  33 T (second restriction portion/first restriction portion) of the rivet  33  and the step portion  17  of the lens  10  engage with each other by means of the only one way of engagement, thereby restricting the direction (that is, the directivity direction of the lens  10 ) of the lens  10  to a specific direction. Accordingly, the LED module MJ according to the example 5 achieves the same function and effect as the LED module MJ according the example 4. Besides, compared with forming the hole  21 , which is the restriction portion, in the mounting substrate  20 , using the rivet  33  which is another member is sometimes able to curb the cost of the LED module MJ. 
       Other Embodiments  
       [0142]    Here, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. 
         [0143]    For example, in the examples 1 to 3, the mechanism for deciding the direction of the lens  10  is the engagement between the pin  11  of the lens  10  and the hole  21  of the mounting substrate  20  (here, such engagement mechanism between the pin  11  and the hole  21  has an advantage of a simple structure.). However, this is not limiting. 
         [0144]    For example, instead of the fitting-in between the pin  11  and the hole  21 , the lens  10  may be provided with a rail; the mounting substrate  20  may be provided with a groove into which the rail is fitted; and thanks to the engagement between the rain and the groove, the direction of the lens  10  may be restricted to a specific direction (in short, the connection between the lens  10  and the mounting substrate  20  may be achieved by a slide mechanism in which the rail and the groove are engageable with each other.)). 
         [0145]    Besides, the number of pins  11  and the number of holes  21 , which decide the position of the lens  10 , are three each in the LED module MJ according to the example  1  and two each in the LED module MJ according to the example 2. On the other hand, in the LED module MJ according to the example 3, the number of pins  11  and the number of holes  21 , which decide the position of the lens  10 , are one each. 
         [0146]    Besides, in the LED module MJ according to the example 4, the number of step upper portions  16 H of the rear surface  10 B of the lens  10  and the number of recessed portions  26  of the mounting substrate  20 , which decide the position of the lens  10 , are one each. Besides, in the LED module MJ according to the example 5, the number of step portions  17  of the lens  10  and the number of head portions  33 T of the rivet  33 , which decide the position of the lens  10 , are one each. 
         [0147]    As described above, to decide the direction of the lens  10 , the number of members (e.g., pin  11 ) of one type and the number of members (e.g., hole  21 ) of the other type, which engage with each other, may be single or more than one if they are the same in number. According to this, in accordance with necessities of the cost and the like, it is possible to variously change the number and shape of members which engage with each other (in short, in accordance with the cost of the pin  11  and the hole  21  and the like which serve as the restriction portions, the degree of freedom of designing the LED module MJ increases.). 
         [0148]    Besides, in the LED modules MJ according to the example 1 to the example 5, the same kind of lenses  10  are used. However, this is not limiting. For example, to obtain a desired brightness distribution of the light (surface light) from the LED module MJ, a plurality of kinds of lenses  10  (e.g., lenses  10  whose lens surfaces  10 S are different from each other in surface shape) having directivity direction s different from each other may be mounted on the mounting substrate  20  (however, it is possible to arbitrarily set the directivity direction of the lens  10 , accordingly, the number of kinds of the lenses  10  may be relatively small.). 
         [0149]    Besides, the pins  11  may be different for the lenses  10  which are different in directivity direction, in accordance with which, the holes  21  of the mounting substrate  20  may be different. In short, when a plurality of kinds of lenses  10 , which are different from each other in directivity direction, are used, it is desirable that different kinds of the pins  11  and the like are formed on the lens  10  for different kinds of the lenses  10 ; and in accordance with each of the different kinds, a different kind of the hole  21  and the like of the mounting substrate  20  are used. 
         [0150]    A reason for this is that according to this, mis-mounting (in other words, mis-positioning) of the different kinds of the lenses  10  is solved. 
         [0151]    Of course, for example, as in the LED module MJ according to the example 3, the single kind of the pin  11 D is used; in accordance with the single kind of the pin  11 D, the single kind of the hole  21 D is used; and as a result of which, a single kind of combination of the pin  11  and the hole  21 D corresponding to each other may be used. In short, when the same kind of the lenses  10  having the same directivity direction are used, the number of kinds of the pins  11  and the like formed on all the lenses  10  may be single; and in accordance with the single kind, the number of kinds of the holes  21  and the like of the mounting substrate  20  may be single (however, the directions of the holes  21  of the mounting substrate  20  are variously different.). 
         [0152]    A reason for this is that according to this, only one kind of the lenses  10  are incorporated in the LED module MJ, accordingly, the cost of the LED module MJ is curbed. 
         [0153]    Besides, in the above description, the pin  11  is formed on the lens  10  and the hole  21  is formed in or through the mounting substrate  20 ; however, this is not limiting. For example, the pin  11  may be formed on the mounting substrate  20  and the hole  21  may be formed in or through the lens  10 . In short, if the direction of the lens  10  is able to be restricted on the mount surface  20 U of the mounting substrate  20 , the restriction portions such as the pin  11  and the hole  21 , which engage with each other, may be formed on any of the lens  10  and the mounting substrate  20 . 
       REFERENCE SIGNS LIST 
       [0154]      10  lens 
         [0155]      10 B rear surface of lens 
         [0156]      10 S lens surface of lens 
         [0157]    DH housing concave 
         [0158]      11  pin (one or the other restriction portion, first restriction portion/second restriction portion) 
         [0159]      12  shank portion of pin 
         [0160]      13  engagement piece of pin 
         [0161]      16  step (one or the other restriction portion, first restriction portion/second restriction portion) 
         [0162]      16 H step upper portion 
         [0163]      16 L step lower portion (one or the other restriction portion, first restriction portion/second restriction portion) 
         [0164]      17  step portion (one or the other restriction portion, first restriction portion/second restriction portion) 
         [0165]      20  mounting substrate 
         [0166]      20 U mount surface 
         [0167]      20 B rear surface opposite to mount surface 
         [0168]      21  hole (one or the other restriction portion, second restriction portion/first restriction portion) 
         [0169]      26  recessed portion (one or the other restriction portion, second restriction portion/first restriction portion) 
         [0170]      31  LED (light-emitting element) 
         [0171]      33  rivet (one or the other restriction portion, second restriction portion/first restriction portion) 
         [0172]      41  backlight chassis 
         [0173]      41 B bottom surface of backlight chassis 
         [0174]      42  reflection sheet 
         [0175]      43  diffusion plate 
         [0176]      44  prism sheet 
         [0177]      45  micro-lens sheet 
         [0178]      49  backlight unit (illumination device) 
         [0179]      59  liquid crystal display panel (display panel) 
         [0180]      69  liquid crystal display device (display device) 
         [0181]      89  liquid crystal television (television receiver)