JP5532815B2 - Lighting device, projector and electronic device - Google Patents

Description

  The present invention relates to a lighting device, a projector, and an electronic apparatus.

  The basic components of the lighting device are a light source composed of a plurality of LED arrays, a light guide that guides light from the light source to the display panel, and a display panel that is an irradiated body. As an illumination device that uniformly illuminates the display panel, there is a technique in which light from an LED is incident on a light guide and the intensity distribution of the light is made uniform while propagating through the light guide. For example, as shown in FIG. 21, light from a plurality of LEDs 609 is incident on a light guide 601 in which the size of the light incident end surface 601 a and the light exit end surface 601 c is approximately the same as the display area 603 A of the display panel 603. An illumination device 600 that makes the light intensity distribution on the light exit end surface 601c uniform is known (for example, Patent Document 1). The light emitted from each LED 609 enters the light guide 601 from the light incident end surface 601 a of the light guide 601.

  For example, as shown in FIG. 22, the light ray RA1 emitted from the LED (A) is totally reflected by the side surface 601b of the light guide 601 to become a light ray RA2. The light beam RB1 emitted from the LED (B) is totally reflected by the side surface 601b of the light guide 601 and becomes a light beam RB2. In this way, the light propagates through the light guide 601 so that the light intensity distribution is made uniform, and the display region 603A of the display panel 603 can be illuminated uniformly.

  In the light guide 601, the light incident end surface 601 a and the light exit end surface 601 c have substantially the same size as the display area 603 A of the display panel 603. The light source 608 includes a plurality of LEDs 609 arranged in a region corresponding to the light incident end surface 601a of the light guide 601. However, with this configuration, the number of LEDs 609 is limited to the number that can be accommodated in the area of the light incident end surface 601a of the light guide body 601, and thus there is a problem in that there is a limit to improving the illuminance of light that illuminates the display panel 603.

  Therefore, in order to increase the illuminance, Patent Documents 2 and 3 disclose configurations in which more LEDs are arranged in a region larger than the area of the light incident surface of the light guide and light from each LED is incident on the light guide. Has been.

JP 2007-4197 A JP 2005-274836 A JP 2006-208894 A

  However, since LEDs are arranged on a plurality of substrates and incident from a plurality of surfaces of the light guide or LEDs are arranged in a curved shape, there is a problem that the mounting of the LEDs is complicated.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an illumination device capable of obtaining brighter illumination light with a simple configuration, a bright projector with high display quality, and an electronic apparatus. One.

In order to solve the above-described problems, the illumination device of the present invention has a light guide body in which the areas of the light incident end face and the light exit end face facing each other are relatively larger than the area of the display area in the irradiated body, and a substrate When, and a LED provided on the light incident face and the opposing surfaces of the light guide in the substrate, substantially equal to the light emitting area as the light input end face disposed light incident face side of the light guide and a light source having a to light emitting end of the light guide, the first light outgoing side reflecting member having an opening area substantially equal to the area of the display region of the object to be irradiated is provided, the light guide The light incident end face is provided with a first light incident side reflecting member having a second opening at a position corresponding to the LED. On the substrate, a third light incident side reflecting member is disposed at a position corresponding to the LED. A second light incident side reflecting member having an opening is provided, and the second opening has a front It is larger than the third opening.

In the present invention, the light guide body is provided with a light guide body in which the areas of the light incident end face and the light exit end face facing each other are relatively larger than the area of the display area in the irradiated body, so that more light is contained inside the light guide body. It is possible to make it incident. The light incident on the light guide is directed toward the light exit end face while propagating through the light guide, reflected by the light exit side reflecting member provided on the light exit end face, and further provided on the light entrance end face. The light is reflected again by the incident light reflecting member and emitted from the first opening having an area substantially equal to the area of the display area formed on the light exit end face toward the irradiated object. Thus, the light incident on the light guide can be used as illumination light for the irradiated object without being wasted.
Therefore, the illumination apparatus can obtain brighter illumination light with a simple configuration.

Moreover, it is preferable that the light source has a plurality of LEDs arranged in a planar shape in a region corresponding to the light incident end surface of the light guide.
According to the present invention, a light guide that has a relatively large area between the light incident end face and the light exit end face that are relatively larger than the area of the display area of the irradiated object, and more LEDs with a simple configuration. Can be used as illumination light. Thereby, it becomes a brighter illumination device with high illuminance.

Moreover, it is preferable that the said light-incidence end surface of the said light guide is provided with the 1st said light-incidence side reflection member which has several 2nd opening in the position corresponding to these LED.
According to the present invention, the light incident end face of the light guide is provided with the first light incident side reflecting member having a plurality of second openings at positions corresponding to the plurality of LEDs. The light from the LED can be efficiently taken into the light guide, and the reflected light (return light) from the light exit end face side is not leaked from the light entrance end face side to the first opening on the light exit end face side. It is possible to reflect efficiently toward the screen.

The light source includes a substrate and the plurality of LEDs arranged in a planar shape on a surface of the substrate facing the light incident end surface of the light guide, and the plurality of LEDs are disposed on the substrate. It is preferable that a second light incident side reflecting member having a plurality of second openings is provided at a position corresponding to.
According to the present invention, since the second light incident side reflecting member having the second opening corresponding to the LED is provided on the light source side, there is no possibility of blocking the light of the LED, and from the light emitting end surface side. It is possible to reflect the reflected light toward the first opening.

Moreover, it is preferable that the side surface of the light guide body is a total reflection surface that totally reflects light incident from the light source.
According to the present invention, since the side surface of the light guide body is a total reflection surface that totally reflects light incident from the light source, it is possible to prevent light from leaking outside from the side surface.

In addition, it is preferable that a light absorbing member is disposed outside the light guide body so as to cover the entire side peripheral surface and be spaced from the side surface.
According to the present invention, the light absorbing member is disposed so as to cover the entire side peripheral surface of the light guide and to be spaced from the side surface. Can block light. The light absorbing member can also prevent light from leaking around the light guide when there is light scattered inside the light guide.

Further, it is preferable that a support member for supporting the light guide is provided on the light incident end face of the light guide.
According to the present invention, since the support member for supporting the light guide is provided on the light incident end face of the light guide, it can be attached to a predetermined installation place without impairing the light guide function. It becomes.

The light guide has a width in the short side direction of the light incident end face and the light outgoing end face substantially equal to an effective display width of the display area of the irradiated member, and a length of the light incident end face and the light outgoing end face. It is preferable that the width in the side direction is a size having an integral multiple of the effective display width of the display area.
According to the present invention, it is possible to capture more light from the LED, compared to a conventional light guide whose light incident end face and light exit end face have an area substantially equal to the area of the display area of the irradiated object. It is.

Further, the light guide has a width in the long side direction of the light incident end surface and the light exit end surface substantially equal to an effective display width of the display region of the irradiated member, and a short length of the light incident end surface and the light exit end surface. It is preferable that the width in the side direction is a size having an integral multiple of the effective display width of the display area.
According to the present invention, it is possible to capture more light from the LED, compared to a conventional light guide whose light incident end face and light exit end face have an area substantially equal to the area of the display area of the irradiated object. It is.

In addition, the first light incident side reflecting member and the second light incident side reflecting member are provided, and the first light incident side reflecting member is more than the second opening of the second light incident side reflecting member. It is preferable that the first opening is larger.
According to the present invention, since both the first light incident side reflecting member and the second light incident side reflecting member are provided, the reflected light from the light exit end face side of the light guide is reflected in the first and second light reflecting members. It is possible to more reliably reflect the light incident side reflecting member 2 toward the first opening side. Thereby, it becomes a much brighter illuminating device.

Moreover, it is preferable that the reflection member which covers the whole side peripheral surface is provided in the outer side of the said light guide.
According to the present invention, since the reflecting member that covers the entire side peripheral surface is provided outside the light guide, external light incident on the inside of the light guide from the side surface of the light guide can be blocked. In addition, it is possible to prevent light from leaking around the light guide when there is light scattered inside the light guide.

Moreover, it is preferable that the said light guide consists of a cylindrical body which made the said light-incidence end surface side the opening end, and the reflection member which covers the whole side peripheral surface is provided in the outer side of the said light guide.
According to the present invention, the light guide is made of a cylindrical body having the light incident end face side as an open end, and a reflecting member that covers the entire side peripheral surface is provided outside the light guide. It is possible to reduce the weight of the entire light guide. Moreover, even if it is a light guide body of a hollow structure, it is possible to implement | achieve reflection by a side surface with a reflection member.

Moreover, it is preferable that the said light source is a surface light source which consists of an organic EL element.
According to the present invention, brighter illumination light can be obtained even when a surface light source made of an organic EL element is used.

A projector of the present invention is the illumination device according to any one of claims 1 to 12, a display element that modulates light emitted from the illumination device, and a projection light source system that projects light modulated by the display element. And.
According to the present invention, since the above-described illumination device is provided, a projector with higher display quality that is brighter and more visible can be obtained.

An electronic apparatus according to the present invention includes the projector described above.
According to the present invention, an electronic device with high product performance can be obtained because the projector is provided with a brighter and more visible projector with high display quality.

1 is a schematic configuration diagram of a projector of the present invention. The perspective view which shows schematic structure of the illuminating device in this projector. (A) is a top view which shows the light-incidence end surface of the light guide seen from the light source side, (b) is AA sectional drawing of (a). (A) is a top view which shows the light emission end surface of the light guide seen from the liquid crystal display element side, (b) is BB sectional drawing of (a). Sectional drawing in the optical axis direction of an illuminating device. The figure for demonstrating the lower limit of the inclination of the side surface with respect to the light-incidence end surface and light-emitting end surface of a light guide. It is a figure which shows schematic structure of the illuminating device of 2nd Embodiment, Comprising: The perspective view seen from the liquid crystal display element side. It is a figure which shows schematic structure of the illuminating device of 2nd Embodiment, Comprising: The perspective view seen from the light source side. The figure explaining the structure of the light source side reflective mirror formed in the circumference | surroundings of LED. Sectional drawing in the optical axis direction of an illuminating device. The perspective view which shows schematic structure of the illuminating device of 3rd Embodiment. (A) is the top view seen from the light-incidence end surface side of a light guide, (b) is DD sectional drawing of Fig.12 (a). The perspective view which shows schematic structure of the illuminating device of 4th Embodiment seen from the liquid crystal display element side. The perspective view which shows schematic structure of the illuminating device of 5th Embodiment seen from the liquid crystal display element side. (A) is a top view which shows the light-incidence end surface of the light guide seen from the light source side, (b) is EE sectional drawing of (a). (A) is the top view seen from the light-incidence end surface side of a light guide, (b) is FF sectional drawing of (a). (A) is the top view seen from the light-incidence end surface side of a light guide, (b) is GG sectional drawing of (a). 1 is a schematic configuration diagram of a projector. The schematic block diagram of the head-up display which is one Embodiment of an electronic device. The figure which looked at the image of the head up display from the vehicle driver's seat. The perspective view which shows schematic structure of the conventional illuminating device. Sectional drawing in the optical axis direction of the conventional illuminating device.

Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.
FIG. 1 is a schematic configuration diagram of a projector according to the present embodiment.

  As shown in FIG. 1, the projector 1 of the present embodiment includes an illumination device 2, a liquid crystal display element 3 (display element), a projection lens 4 (projection optical system), and a screen 5. The illuminating device 2 emits light to irradiate the liquid crystal display element 3 which is an object to be irradiated. The liquid crystal display element 3 has a liquid crystal layer sandwiched between a pair of substrates, and a liquid crystal drive signal (video signal) is supplied from a driver (not shown). The incident light from the illumination device 2 can be optically modulated according to the logic state of the drive signal and output as an image. The projection lens 4 is designed so that an image light-modulated by the liquid crystal display element 3 can be formed on the screen 5. The screen 5 is translucent and is configured to be able to diffusely reflect light, and a display image can be observed from the opposite side of the projection lens 4. Then, the image light modulated by transmitting through the liquid crystal display element 3 is enlarged and projected by the projection lens 4 and projected and displayed on the screen 5.

Here, the illumination device of the present embodiment will be described in detail with reference to FIG. FIG. 2 is a perspective view showing a schematic configuration of the illumination device in the projector.
As shown in FIG. 2, the lighting device 2 includes a light guide 7 and a light source 8 including a plurality of LED arrays, and is emitted from the light source 8 disposed on the light incident end surface 7 a side of the light guide 7. Light enters the light guide 7.

  The light source 8 has a light emission area substantially equal to the area of the light incident end surface 7 a of the light guide 7. The light source 8 is a point light source in which a plurality of LEDs 9 are arranged in a planar shape on the LED substrate 14. The light source 8 is separate from the light guide 7, and the light exit side surface is a light incident end surface 7 a of the light guide 7. It is arranged with the posture toward the side. In the present embodiment, nine times as many LEDs 9 are used as compared to the conventional configuration in which a total of 12 LEDs in 3 rows and 4 columns are used. Here, about 108 LEDs 9 that emit white light are used, and are integrated in a plane (for example, two-dimensionally) in the same area as the light incident end surface 7a of the light guide 7 on the same substrate and arranged at equal intervals. is there.

  The light guide 7 is made of a transparent resin such as acrylic or glass, and has a rectangular parallelepiped shape in which the areas of the light incident end face 7a and the light outgoing end face 7c facing each other in the light propagation direction are equal to each other, and effective display of the liquid crystal display element 3 The area of the light incident end face 7a and the light exit end face 7c is relatively larger than that of the region 3A. Here, the display area 3A in the liquid crystal display element 3 is an effective light modulation area in which a plurality of pixels (not shown) are arranged in a matrix, and this display area 3A (effective light modulation area) is substantially. This is an area contributing to display.

  The size of the light guide 7 is such that the width (W1) in the lateral direction (horizontal direction) of the light incident end face 7a is such that twelve LEDs 9 can be arranged at a predetermined pitch P (3 mm), in this case 39 mm. It has become. Further, the height H1 of the light incident end face 7a is a length corresponding to nine LEDs 9 arranged at a predetermined pitch P (3 mm), and is 30 mm here. Furthermore, the total length L1 (length in the light propagation direction) of the light guide 7 is 30 mm, and the light from each LED 9 propagates in the light guide 7 and is emitted from the light exit end face 7c with sufficiently uniform intensity. It is set to such a length.

  As described above, since the light guide 7 has a rectangular parallelepiped shape, the side surface 7b connecting the light incident end surface 7a and the light output end surface 7c is substantially perpendicular to the light incident end surface 7a and the light output end surface 7c. The side surface 7 b is a total reflection surface that totally reflects the propagation light inside the light guide 7. That is, the light incident from the light incident end surface 7a side is totally reflected at the side surface 7b and does not leak outside. In consideration of the dimensional error of the shape at the time of manufacture, for example, the inclination θ of the side surface 7b with respect to the light incident end surface 7a and the light output end surface 7c is a range in which the light incident on the light guide 7 is totally reflected on the side surface 7b. It should just be 7 degrees or less (refer to Drawing 6).

  In the light guide 7 of the present embodiment, reflection mirrors 10 and 11 are provided on the light incident end surface 7a and the light exit end surface 7c, respectively. The light incident end face 7a is provided with a light incident side reflecting mirror 10 (first light incident side reflecting member) having a plurality of LED openings 10A (second openings) facing the plurality of LEDs 9. The LED opening 10 </ b> A has a square shape having an opening area larger than the light emitting area of the LED 9, and is set to a size that does not block light incident on the light guide 7 from the LED 9.

  Further, the light exit end face 7c is provided with a light output side reflection mirror 11 (light output side reflection member) having an emission opening 11A (first opening) for emitting light propagated in the light guide 7 at the center. It has been. The size of the emission opening 11A is set corresponding to the size of the display area 3A of the liquid crystal display element 3, and in this embodiment, the display area 3A of the liquid crystal display element 3 arranged facing the emission opening 11A is uniform. The display area 3A has a size substantially equal to that of the display area 3A.

  The light incident side reflection mirror 10 and the light emission side reflection mirror 11 are formed by a method of depositing a metal such as aluminum using a mask pattern for shielding the LED opening 10A or the light emission opening 11A. Or after forming a metal thin film on the board | substrate different from the light guide 7, you may form by bonding together to the light-incidence end surface 7a or the light-emitting end surface 7c, respectively.

  As shown in FIG. 2, a support member 13 that supports the entire light guide 7 is provided on the light incident end surface 7 a of the light guide 7. Since the side surface 7b of the light guide body 7 has a function of totally reflecting light, when the light guide body 7 is supported using a support member, the support member is brought into contact with the side surface 7b of the light guide body 7. I can't let you. Therefore, when attaching the support member 13 to the light guide 7, it is necessary to arrange the support member 13 at a position that does not hinder the mixing of light within the light guide 7. For this reason, in this embodiment, as shown in FIG. 2, the support members 13 are arranged in the four corners of the light incident end surface 7 a and in the region other than the LED opening 10 </ b> A of the light incident side reflection mirror 10. Since the light incident end surface 7a of the light guide 7 is covered with the light incident side reflection mirror 10, the support member 13 may be disposed in a region other than the LED opening 10A. The support member 13 may be formed integrally with the light guide 7. Such a support member 13 can be attached to a predetermined installation place without impairing the function of the light guide 7.

  Moreover, since the light source 8 described above has a configuration in which a large number of LEDs 9 are densely arranged on the LED substrate 14, the entire LED substrate 14 generates heat. For this reason, it is preferable to cool with a cooling element using a fan, a heat sink or a Peltier effect.

Next, the structures of the light incident side reflection mirror and the light output side reflection mirror will be described in detail.
FIG. 3A is a plan view showing a light incident end face of the light guide viewed from the light source side, and FIG. 3B is a cross-sectional view taken along line AA in FIG. In FIG. 3A, only the LED is shown, and the LED substrate is omitted.

First, the light incident side reflection mirror 10 will be described.
As shown in FIGS. 3A and 3B, in this embodiment, the vertical and horizontal widths W2 of the light emitting regions 9A of the LEDs 9 are each 1 mm, and the light incident end surface 7a of the light guide 7 from the light emitting surface 9a of the LEDs 9. When the distance S up to 0.1 mm is assumed to be incident on the light guide 7 with ambient light up to a light emission angle θ of 80 ° in the LED 9, a certain distance (d = 0) from the side edge of the LED 9 in the surface direction. .57 mm) of light needs to be incident on the light guide 7.

  Therefore, when the distance a from the side edge of the LED 9 to the opening edge of the LED opening 10A in the plan view is 0.6 mm, which is slightly larger than the distance d, the length L2 of each side of the LED opening 10A is obtained by W2 + 2 × a. If the actual value is entered, it becomes 2.2 mm.

  As shown in FIG.3 (b), even if the light emission angle (theta) in LED9 is 80 degrees, if it injects into the light guide 7, the critical angle determined by the light guide material (the light guide 7 is glass, If the refractive index is 1.52, the critical angle is 41.1 °), which is incident on the side surface 7b of the light guide 7 so that the light incident on the light guide 7 from the LED 9 7 or each reflecting mirror 10 (11), the light is totally reflected by the side surface 7b of the light guide 7 without being scattered by the reflecting mirror 10 (11). Can be propagated.

  Since the pitch P of each LED 9 in the LED array is 3 mm, the width (the distance between the LED openings 10A) W3 of the light incident side reflection mirror 10 is 0.8 mm. The light incident side reflecting mirror 10 reflects again the light reflected and returned by the light emitting side reflecting mirror 11, and propagates the light to the light emitting end face 7 c side of the light guide 7 again.

  In addition, although the case where the shape of LED opening 10A was a square was demonstrated, a rectangle, a polygon, or a circle may be sufficient as long as the light which injects into LED 7 from LED9 is not blocked.

Next, the exit aperture 11A of the exit side reflection mirror 11 will be described. 4A is a plan view showing the light exit end face 7c of the light guide 7 viewed from the liquid crystal display element 3, and FIG. 4B is a cross-sectional view taken along the line BB in FIG.
As shown in FIGS. 4 (a) and 4 (b), the size of the exit opening 11A provided on the light exit end face 7c side of the light guide 7 of the present embodiment is 15 mm in the lateral (horizontal) width W4. Thus, the number of LEDs 9 (4 pieces) × predetermined pitch P (3 mm) = 12 mm is covered, the width W5 in the vertical direction (vertical direction) is 12 mm, and the number of LEDs 9 (3 pieces) × predetermined pitch P (3 mm). ) = 9 mm is covered. The size of the display area 3A of the liquid crystal display element 3 used in the present embodiment is 0.7 inches diagonal, the width W6 in the horizontal direction is 14.2 mm, and the width W7 in the vertical direction is 10.7 mm. . The size of the exit opening 11A of the light guide 7 is substantially equal to or slightly larger than the display area 3A of the liquid crystal display element 3.

FIG. 5 is a cross-sectional view of the illumination device 2 in the optical axis direction.
As shown in FIG. 5, the light emitted from each LED 9 of the illumination device 2 passes through the LED opening 10 </ b> A of the light incident side reflection mirror 10 and enters the light guide 7. The light propagating in the light guide 7 reaches the exit opening 11A as it is, and if there is light that exits, the light is totally reflected on the side surface 7b and reflected on the light output side reflection mirror 11 and the light incident side reflection mirror 10. There is also light that repeatedly reaches the exit opening 11A and exits. Thus, the light finally emitted from the emission opening 11A becomes illumination light for illuminating the liquid crystal display element 3.

  Here, when the arrangement of the LEDs 9 is the same as that of the conventional configuration, the virtual boundary indicated by the broken line in FIG. 5 corresponds to the size of the light guide body (FIG. 22) of the conventional configuration. In the conventional configuration, the light rays RA1 and RB1 emitted from the LEDs (A) and (B) are totally reflected by the side surface 601b of the light guide 601 and become light rays RA2 and RB2, which contribute to the mixing of the light intensity ( 22), in the configuration of this embodiment, the light rays RA1 and RB1 travel straight without being reflected at the position of the virtual boundary, and after being reflected between the light output side reflection mirror 11 and the light input side reflection mirror 10. The light exits from the exit opening 11A. The light beams RE2 and RF2 from the LEDs (E) and (F) arranged at the positions of the mirror images of the LEDs (A) and (B) with respect to the virtual boundary perform the same functions as the conventional RA2 and RB2, respectively. The light intensity distribution is made uniform.

  As described above, the illumination device 2 of the present embodiment includes the light guide 7 having an area where the light incident end face 7a and the light exit end face 7c are relatively larger than the area of the display region 3A of the liquid crystal display element 3, By using the light source 8 having a light emission area substantially equal to the area of the light incident end face 7a of the light guide 7, more light from the LEDs 9 can be used as illumination light with a simple configuration. Thereby, it becomes the projector 1 provided with the illuminating device 2 with high illuminance and brighter, and can display a bright image with high display quality.

  Although the first embodiment has been described above, a diffusion plate for further uniformizing the intensity distribution of the light emitted from the emission opening 11A between the emission opening 11A of the light guide 7 and the liquid crystal display element 3. Or you may arrange | position a diffusion sheet (all are not shown). Further, a prism sheet (not shown) may be disposed between the diffusion plate or the diffusion sheet and the liquid crystal display element 3 in order to enhance the directivity of the light diffused by the diffusion plate or the diffusion sheet.

  Further, a lens (not shown) is inserted between the exit opening 11A of the light guide 7 and the liquid crystal display element 3, and an image of the exit opening 11A is formed on the surface of the liquid crystal display element 3 to illuminate the liquid crystal display element 3. You may do it.

  The basic configuration of the projector of each embodiment described below is substantially the same as that of the above embodiment, but is different in the configuration of the illumination device. Therefore, in the following description, it demonstrates focusing on the structure of an illuminating device. Moreover, in each drawing used for description, the same code | symbol shall be attached | subjected to the same component as FIGS.

(Second Embodiment)
Next, 2nd Embodiment which concerns on the illuminating device of this invention is described using FIGS. 7-10.
The illuminating device 30 of this embodiment is different from that of the first embodiment in that a light source side reflection mirror (second light incident side reflection member) 20 is provided not on the light guide 7 side but on the light source 8 side.
7 is a perspective view seen from the liquid crystal display element 3 side in the illumination device 30 of the present embodiment, FIG. 8 is a perspective view seen from the light source 8 side, and FIG. 9A is a schematic configuration of the light source side reflecting mirror 20. The top view to show, (b) is CC sectional drawing of (a).

In the following description, the configuration of the light source side reflection mirror 20 will be described in detail, and the configuration of the light guide 7 and the light output side reflection mirror 11 is the same as that of the first embodiment, and the description thereof will be omitted.
The light source side reflecting mirror 20 of this embodiment has the same function as the light incident side reflecting mirror 10 described in the first embodiment, and is not a light source 7 side as shown in FIGS. 7 and 8. It is provided on the 8th side. Therefore, no reflecting member is provided on the light incident end surface 7a of the light guide 7, and the whole is a transparent incident surface (FIG. 8).

  Specifically, the light source side reflection mirror 20 is composed of a substrate 21 and an LED peripheral mirror 22 made of a metal thin film formed on the surface 21a by a vapor deposition method or the like. The substrate 21 is formed with an opening 21 </ b> A that exposes each LED 9 on the LED substrate 14. The LED peripheral mirror 22 is formed on the surface 21a of the substrate 21 and is formed in a cross-beam shape so as to expose the light emission surface side of each LED 9 on the LED substrate 14. Here, as the substrate 21 on which the metal thin film is deposited, a substrate made of a transparent resin such as acrylic that is easy to process and has an insulating property is preferable. As a result, as shown in FIG. 9, the distance a between the end portion of the LED 9 and the LED peripheral mirror 22 becomes about 0.1 mm, and the distance can be made smaller than in the above embodiment. Becomes 1.8 mm, which is a mirror having a wider reflection region than the light incident side reflection mirror 10 of the first embodiment. Further, the LED opening 20A of the light source side reflection mirror 20 has a square shape that is slightly larger than the outer dimension of the LED 9, and has a vertical and horizontal width W8 of 1.2 mm.

  Such a light source side reflection mirror 20 is a light source that covers the peripheral region of each LED 9 on the surface 14 a of the LED substrate 14 with the LED peripheral mirror 22 facing the light incident end surface 7 a side of the light guide 7. 8 is attached. Each LED 9 is disposed in the LED opening 20 </ b> A of the light source side reflection mirror 20, and the light emission surface of the LED 9 substantially coincides with the surface of the LED peripheral mirror 22 in this state.

  As shown in FIG. 10, the light emitted from each LED 9 of the light source 8 enters the light guide 7 from the light incident end surface 7 a and is totally reflected on the side surface 7 b, and then enters the light by the light output side reflection mirror 11. Reflected toward the end face 7a side. The return light that has returned inside the light guide 7 once exits from the light incident end surface 7a, then is reflected by the light source side reflection mirror 20 (LED peripheral mirror 22) on the light source 8 side, and again in the light guide 7 Is incident on the light exit end surface 7c (outgoing opening 11A) and exits from the exit opening 11A to illuminate the liquid crystal display element 3.

  Since the light source side reflection mirror 20 of the present embodiment has a larger reflection area than the light incident side reflection mirror 10 of the first embodiment, more light can be reflected to the light output end face 7c side, and the light can be guided. It is possible to increase the amount of light that illuminates the liquid crystal display element 3 by the light that has been propagated through the body 7 and combined and emitted from the emission opening 11A. That is, the illumination device 30 that can illuminate the liquid crystal display element 3 with brighter light can be provided.

(Third embodiment)
Next, 3rd Embodiment which concerns on the illuminating device of this invention is described using FIG.11 and FIG.12. FIG. 11 is a perspective view showing a schematic configuration of the illumination device of the present embodiment, FIG. 12A is a plan view seen from the light incident end face side of the light guide, and FIG. 12B is FIG. It is DD sectional drawing of a).
As shown in FIG. 11, the illuminating device 40 of the present embodiment includes a light absorbing member 31 that surrounds the circumferential direction so as to cover the entire side surface outside the light guide body 7, and from the side surface 7 b of the light guide body 7. The configuration is such that external light incident on the inside of the light guide 7 can be blocked. Further, the light absorbing member 31 can prevent light from leaking around the light guide 7 when there is light scattered inside the light guide 7.

  Since the light is totally reflected at the side surface 7b of the light guide body 7, as shown in FIGS. 12 (a) and 12 (b), each side surface is arranged so that the light absorbing member 31 does not contact the side surface 7b of the light guide body 7. 7b is provided with a gap between them. As the light absorbing member 31, a black cloth or a member coated with black paint can be used.

  12B, the light absorbing member 31 may be extended so as to cover the side periphery of the LED substrate 14 so that light leaking around the light source 8 may be shielded. Moreover, you may apply the light absorption member 31 to the said embodiment.

(Fourth embodiment)
Next, 4th Embodiment which concerns on the illuminating device of this invention is described using FIG. FIG. 13 is a perspective view showing a schematic configuration of the illumination device of the present embodiment as viewed from the liquid crystal display element side.
The illuminating device 50 of this embodiment differs in the structure of a light guide and a light source from said each embodiment.
As shown in FIG. 13, the light guide 52 provided in the illumination device 50 of the present embodiment has a width (height H) in the short side direction of the light incident end face 52 a and the light outgoing end face 52 c in the display area 3 </ b> A of the liquid crystal display element 3. And the width of the light incident end face 52a and the light exit end face 52c in the long side direction is an integral multiple of the effective display width of the display area 3A.
Specifically, the width W in the long side direction (x direction) of the light incident end face 52a and the light outgoing end face 52c is the opening width W in the long side direction of the emission opening 11A formed corresponding to the outer shape of the liquid crystal display element 3. And the height H is approximately the same as the width of the exit opening 11A in the short side direction, and is not a rectangular parallelepiped shape as shown in the above embodiments. The whole has a flat plate shape (right columnar shape).
On the light incident end face 52a side of such a light guide 52, a light source 53 having a total of 36 LEDs 9 in 12 rows and 3 rows in a row so that the LED arrangement corresponds to the entire light entrance end surface 52a. Is arranged.

  Unlike the first and second embodiments described above, the illuminating device 50 of the present embodiment has an emission opening 11A that includes a light source 53 and a light guide 52 each having an LED array expanded only in the horizontal direction (x direction). It is the structure which reinforces the light radiate | emitted from.

(Fifth embodiment)
Next, 5th Embodiment which concerns on the illuminating device of this invention is described using FIG. FIG. 14 is a perspective view showing a schematic configuration of the illumination device of the present embodiment as viewed from the liquid crystal display element side.
As shown in FIG. 14, the light guide 62 provided in the illumination device 60 of the present embodiment has a width W in the long side direction (x direction) of the light incident end face 62 a and the light outgoing end face 62 c in the outer shape of the liquid crystal display element 3. The shape is such that the size of the exit opening 11A formed correspondingly is about the same as the opening width in the long side direction, and the height H is about three times the opening width in the short side direction of the exit opening 11A. ing. On the light incident end face 62a side of the light guide 62, a light source 63 having a total of 36 LEDs 9 in three rows and twelve rows is arranged so that the LED arrangement corresponds to the entire light incident end face 62a. Has been.

  Unlike the first and second embodiments described above, the illumination device 60 of the present embodiment has an LED array and a light guide 62 that are expanded only in the height direction (vertical direction) from the opening region of the emission opening 11A. Therefore, the light emitted from the emission opening 11A is enhanced.

(Modification 1)
Next, Modification 1 according to the lighting device of the present invention will be described with reference to FIG. 15A is a plan view showing a light incident end face of the light guide viewed from the light source side, and FIG. 15B is a cross-sectional view taken along line EE of FIG.
The illuminating device 70 in the modification 1 has a configuration in which both the light incident side reflection mirror 10 and the light source side reflection mirror 20 are provided, and the LED openings 10A and 20A face each other. As described above, the LED opening 10 </ b> A of the light incident side reflection mirror 10 has a relatively larger shape than the LED opening 20 </ b> A of the light source side reflection mirror 20, and thus propagates through the light guide 7. Of the return light reflected and returned by the light output side reflection mirror 11, the light rereflected by the light incident side reflection mirror 10 and the light source side reflection after exiting the light guide 7 from the LED opening 10 </ b> A. Some light is re-reflected by the mirror 20. That is, since the light leaked from the light guide 7 without being reflected by the light incident side reflection mirror 10 can be effectively used, the illuminance can be increased as compared with the case of only the light incident side reflection mirror 10.

  However, since it is less loss if the light is reflected from the light incident end face 7 a without being emitted from the light guide 7, the light source side reflection mirror 10 is provided with the light incident side reflection mirror 10 rather than the light source side reflection mirror 20 alone. preferable.

(Modification 2)
Next, Modification 2 according to the lighting device of the present invention will be described with reference to FIG. 16A is a plan view seen from the light incident end face side of the light guide, and FIG. 16B is a cross-sectional view taken along line FF in FIG.
As shown in FIGS. 16A and 16B, the illumination device 80 according to the second modification includes a reflective member 81 formed of a metal thin film or the like so as to cover the entire side surface 7 b on the outer surface side of the light guide 7. Is provided. The reflecting member 81 may be formed by a method of vapor-depositing a metal such as aluminum, or may be formed by forming a metal thin film on a substrate different from the light guide 7 and then bonding it to each side surface 7b. May be. It is also possible to form the light output side reflecting mirror 11 provided on the light output end surface 7c of the light guide 7 at the same time.

  As described above, by providing the reflecting member 81, it is possible to block outside light incident on the inside of the light guide 7 from the side surface 7 b of the light guide 7, and there is light scattered inside the light guide 7. In this case, it is possible to prevent light from leaking around the light guide 7. Furthermore, it is effective when it is desired to support the side surface 7b of the light guide 7. In addition, when supporting the side surface 7b of the light guide 7, the reflection member 81 is formed only in a portion where a support member (not shown) contacts the side surface 7b of the light guide 7, and total reflection can be used in other portions. Such a configuration is preferable.

(Modification 3)
Next, Modification 2 according to the lighting device of the present invention will be described with reference to FIG. FIG. 17A is a plan view seen from the light incident end face side of the light guide, and FIG. 17B is a GG sectional view of FIG.
As shown in FIGS. 17A and 17B, the illumination device 90 according to Modification 3 includes a hollow light guide 92 including a transparent support 91 having a cavity K therein. The transparent support 91 is made of a transparent resin such as acrylic or glass, and has a cylindrical shape with the light incident end face 92a side as an open end. The light output side reflection mirror 11 is provided on the light output end surface 92 c side of the light guide 92, and the entire side surface 92 b in the circumferential direction of the light guide 92 is covered with the reflection member 81. Yes.
In addition, in the case of the light guide 92 in which the entire side peripheral surface is covered with the reflecting member 81 in this way, it is difficult to form the light incident side reflecting mirror because the light incident end surface 92a side is the open end. The light source 8 including the light source side reflection mirror 20 (FIG. 7) described above is provided.

  According to such a configuration, since the hollow light guide structure is adopted, the entire light guide 92 can be reduced in weight. In the light guide 92 having a hollow structure, total reflection at the side surface 92 b cannot be expected, and thus a reflecting member 81 is required around the transparent support 91. Thereby, it is possible to prevent light from leaking from the light guide 92 to the outside.

  As mentioned above, although several embodiment and modification were demonstrated about the illuminating device of this invention, the number of LED9 and the length or aspect ratio or the aspect ratio of the light-incidence end surface 7a and the light-emitting end surface 7c of the light guide 7 are changed suitably. Is possible.

Further, when a stronger light quantity is required to increase the enlargement ratio of the projected image, as shown in FIG. 18, a projector having a liquid crystal display element and a lighting device for each primary color may be used.
FIG. 18 is a schematic configuration diagram of the projector according to the present embodiment.
As shown in FIG. 18, the projector 100 according to the present embodiment includes three sets of illumination optical systems 102R, 102G, and 102B and three sets of liquid crystal light valves 103R, 103G, and 102B that correspond to the illumination optical systems 102R, 102G, and 102B. 103B (display element), a cross prism 105, a projection optical system 106, and a screen 109 are provided.

The three sets of illumination optical systems 102R, 102G, and 102B emit red (R) light, green (G) light, and blue (B) light, and LEDs that emit light from R, G, and B, respectively. LED light sources 108R, 108G, and 108B (light sources) having the above arrangement, and a light guide rod 107 that guides the color light from the LED light sources 108 toward the optical system at the subsequent stage. As each illumination optical system 102R, 102G, 102B, an illumination device selected from any of the above-described embodiments and modifications is employed.
Each liquid crystal light valve 103R, 103G, 103B modulates each color light incident from each illumination optical system 102R, 102G, 102B. The liquid crystal light valves 103R, 103G, and 103B of the present embodiment have polarizing plates (both not shown) on the light incident side and the light emission side of the liquid crystal display element in which the liquid crystal layer is sandwiched between a pair of substrates. It is arranged.
The cross prism 105 combines the three color lights modulated by the liquid crystal light valves 103R, 103G, and 103B. The projection optical system 106 projects the light combined by the cross prism 105 onto the screen 109.

[Electronics]
FIG. 19 is a schematic configuration diagram of a head-up display 1700 which is an embodiment of the electronic apparatus. FIG. 20 is a view of the image of the head-up display 1700 as seen from the vehicle driver's seat.

  In FIG. 19, a vehicle 270 is a sedan type passenger car. The head-up display 1700 includes an electro-optical device 300, an optical system that projects light (image light) emitted from the electro-optical device 300 on the front window 272, and light projected on the front window 272 to the driver's seat. And a half mirror 274 that reflects toward the screen.

  The electro-optical device 300 is an electro-optical device including the above-described illumination device 2, the liquid crystal display element 3, and the projection lens 4 of the present invention, and is housed inside a dashboard 273. The dashboard 273 is provided with an opening 273H for transmitting light L below the front window 272, and the light L emitted from the electro-optical device 300 through the opening 273H is a half mirror. 274 is projected on the screen. The projected image is visually recognized by the vehicle occupant M as a virtual image I.

  The half mirror 274 is configured as, for example, a sheet-like film, but a part of the light L may be reflected by processing the surface of the front window 272. As shown in FIG. 20, the half mirror 274 is arranged in front of the driver's seat. On the half mirror 274, information such as a speed meter, a remaining amount of gasoline, and a warning are displayed. The occupant M can visually recognize these pieces of information without moving the line of sight greatly during driving.

Here, the electro-optical device 300 includes the configuration of the projector (illumination device) of the present invention described above. Therefore, since the information is clearly displayed regardless of day or night, a comfortable driving environment can be provided.
Note that such a display device can be applied to a head-mounted display that displays a virtual image that is attached to the head and enlarged in front of the eyes.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the previous embodiment, an LED that emits white light is used as an LED. However, a so-called field sequential illumination device and display device in which RGB LEDs are arranged on an LED substrate and the RGB LEDs are sequentially turned on. Can be configured. In this case, it is not necessary to incorporate a color filter in the liquid crystal display element.

  Moreover, as a light source, the following light sources can be used instead of the LED array. For example, a surface light source composed of an organic EL element utilizing an organic EL point light emitting element array or an organic EL linear light emitting element array, a light source utilizing a cold cathode tube array, and the like can be mentioned. When an organic EL linear light source or a rod-shaped cold cathode tube is used, the mirror element on the incident surface side is disposed between adjacent linear light sources or rod-shaped light sources.

  Furthermore, the lighting device of the present invention can be applied not only to the liquid crystal display element but also to other objects to be illuminated.

DESCRIPTION OF SYMBOLS 1 ... Projector 2,40,50,60,70,80,90 ... Illuminating device, 3 ... Liquid crystal display element (irradiated body), 3A ... Display area, 7,52,62,68,82,92 ... Light body, 7a, 52a, 62a, 91a, 92a ... light incident end face, 7b, 68b, 91b, 92b ... side face, 7c, 52c, 62c, 92c ... light exit end face, 8, 53, 63 ... light source, 9 ... LED, DESCRIPTION OF SYMBOLS 10 ... Light-incidence side reflection mirror (1st light-incidence side reflection member), 10A ... Opening (2nd opening), 11 ... Light-emitting side reflection mirror (light-emitting side reflection member), 11A ... Output opening (1st opening) ), 13 ... support member, 14 ... substrate, 20 ... light source side reflection mirror (second light incident side reflection member), 20A ... opening, 21 ... substrate, 21a ... surface, 22 ... LED peripheral mirror, 31 ... light absorption 81, reflecting member, 100, projector, 1700, f Doppup display (electronic equipment), 103R, 103G, 103B ... Liquid crystal light valve (display element), 106 ... Projection optical system

Claims (11)

A light guide having an area where the area of the light incident end face and the light exit end face facing each other is relatively larger than the area of the display region in the irradiated body;
Substrate and has an LED provided at the light incident face and the opposing surfaces of the light guide in the substrate, substantially equal emission to the area of arranged light incident face side of the light guide light input end face A light source having an area,
Wherein the light emitting end of the light guide, the first light outgoing side reflecting member having an opening area substantially equal to the area of the display area of the irradiation object is provided,
The light incident end surface of the light guide is provided with a first light incident side reflecting member having a second opening at a position corresponding to the LED,
On the substrate, a second incident-side reflecting member having a third opening at a position corresponding to the LED is provided,
The lighting device , wherein the second opening is larger than the third opening . The lighting device according to claim 1 , wherein the LED is an organic EL element. The side of the light guide body, the lighting device according possible to claim 1 or 2, characterized in that a total reflection surface that totally reflects the light incident from the light source. According to any one of claims 1 to 3, characterized in that the light absorbing member at a spacing covers the entire side peripheral surface on the outside with the side peripheral surface of the light guide is arranged Lighting device. Lighting device according to any one of claims 1 to 3, characterized in that the reflecting member on the outside of the light guide covers the entire side peripheral surface is provided. The light guide is a light entering end face from the open end and the cylindrical body, claims 1, characterized in that the reflecting member on the outside of the light guide covers the entire side peripheral surface is provided 4. The illumination device according to any one of 3 .   The lighting device according to claim 1, wherein a support member that supports the light guide is provided on a light incident end surface of the light guide. In the light guide, the height of the light incident end face and the light outgoing end face is substantially equal to the height of the display area of the irradiated body , and the width of the light incident end face and the light outgoing end face is the width of the display area. The lighting device according to claim 1, wherein the lighting device is formed in a size having a length that is an integral multiple of. The height of the light guide body, the light incident end face and a width substantially equal and the light incident end face and the height of the light emitting end is the display area of the width of the light emitting end is the display area of the object to be irradiated The lighting device according to claim 1, wherein the lighting device is formed in a size having a length that is an integral multiple of. A lighting device according to any one of claims 1 to 9 ,
A projector comprising: a display element that modulates light emitted from the illumination device; and a projection light source system that projects light modulated by the display element.   An electronic apparatus comprising the projector according to claim 10.

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