JP4788153B2 - Light irradiation device and projector device - Google Patents

Description

  The present invention relates to a light irradiation apparatus and a projector apparatus using a light emitting element as a light source.

  A projector that uses a high-brightness LED as a light source for a projector that projects an image of light (modulated light) that has passed through the light valve is known. (For example, refer to Patent Document 1). By using the LED, there is an advantage that the apparatus can be downsized and the lighting control of the light source can be facilitated as compared with the case of using a halogen lamp or a xenon lamp. However, in order to increase the light emission luminance of the LED, it is necessary to supply a large current to the LED, and there is a risk that the LED will be destroyed by the heat generated by the LED unless heat countermeasures due to heat generation of the LED are taken. Patent Documents 2 and 3 disclose devices that take measures against heat of LEDs.

JP 2000-194275 A JP 2004-4581 A JP 2004-69825 A

  In the techniques disclosed in Patent Documents 2 and 3, since it is necessary to add a heat conductive heat radiating member, a cooling Peltier element, etc., an increase in power consumption due to the Peltier element and an increase in the size of the device may occur. To do.

According to a first aspect of the present invention, in the light irradiation device that emits light from the light emitting element , the light emitting element is disposed substantially in parallel with the installation surface of the light irradiation device and on the back surface of the surface facing the installation surface. And a housing that covers the mounting substrate so that at least a part of the surface facing the installation surface is exposed , and the housing includes the mounting substrate and the installation surface. The mounting board is configured to be movable with respect to the casing so that the distance between the facing surface and the installation surface is variable .
According to a third aspect of the present invention, there is provided a projector device according to the first or second aspect , a light image forming element that modulates light from the light irradiation device to form a light image, and changes an optical path. An optical path changing member and a projection optical system for projecting the optical image formed by the optical image forming element are provided.

  According to the present invention, the light emitting element is mounted on a metal mounting board, the mounting board is disposed substantially parallel to the installation surface of the light irradiation device, and the back surface of the surface on which the light emitting element is mounted, Since the mounting board is covered with a housing so that at least a part of the surface facing the installation surface is exposed, a light irradiation device and a projector device that secure heat dissipation without using a Peltier element and do not impair downsizing Can be provided.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a front view of a liquid crystal projector according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA ′. The projector 100 includes a first casing 11 that accommodates an optical block, and a second casing 12 that serves as a base for the first casing 11. The second casing 12 includes an optical system receiving portion 12s having a part of a spherical surface, and the first casing 11 includes a base contact part 11s having a part of a spherical surface. The optical system receiving portion 12s and the base contact portion 11s are configured to be in surface contact with each other in a slidable manner. Thereby, like the so-called spherical joint, the orientation of the first housing 11 can be adjusted on the second housing 12. The first casing 11 and the second casing 12 are formed of a material having low thermal conductivity such as plastic.

  The configuration of the optical block in the first housing 11 will be described. The high-intensity LED 22 as a light source is mounted on a metal substrate 21. The metal substrate 21 is made of, for example, an aluminum substrate, and the LEDs 22 are mounted on a pattern formed on the thermally conductive insulating layer on the component mounting surface (upper side in FIG. 2) of the substrate 21. The metal substrate 21 is fixed so that a part of the component mounting surface is in contact with the substrate receiving portion D (FIG. 1) of the first housing 11, and the metal portion of the lower surface 21 a of the metal substrate 21 is exposed. .

  The LED 22 illuminates the transmissive liquid crystal panel 23 with brightness according to the current supplied via the harness 20. The liquid crystal panel 23 is driven by a drive signal for reproducing an image or the like supplied via the harness 20. Specifically, a voltage corresponding to the density of the image is applied to the liquid crystal layer for each pixel, the arrangement of liquid crystal molecules in the liquid crystal layer to which the voltage is applied is changed, and the light transmittance of the liquid crystal layer is in pixel units. It changes with. The liquid crystal panel 23 whose transmittance has been changed in this way modulates the light from the LED 22 to generate an optical image. The light beam transmitted through the liquid crystal panel 23 travels upward in FIG. 2 and enters the prism block 32. The liquid crystal panel 23 may be compatible with color display or monochrome display.

  The prism block 32 includes a polarization beam splitter (hereinafter referred to as PBS) in which a polarization separation unit 31 that forms an angle of 45 degrees with respect to the optical axis Ax of the LED light is sandwiched between two triangular prisms 32a and 32b. A reflection mirror 33 is disposed on the right exit surface of the PBS 32 via a quarter-wave plate 34. The reflecting mirror 33 has a reflecting surface formed in a predetermined curved surface (spherical surface or aspherical surface), and constitutes a projection optical system of the projector 100.

  A control circuit board 36 is disposed on the right side of the reflection mirror 33. A drive IC 24 is mounted on the control circuit board 36, and power and control signals are supplied from an external device (not shown) via an external cable (for example, USB cable) 25. The drive IC 24 sends a lighting control of the LED 22 and a signal for driving the liquid crystal panel 23 to the LED 22 and the liquid crystal panel 23 via the harness 20 in accordance with the control signal.

  In the transmitted light beam from the liquid crystal panel 23 that has entered the PBS 32, the S-polarized component of the incident light is reflected by the polarization separator 31 and travels to the right. The reflected light beam traveling rightward is emitted from the PBS 32 and reflected by the reflection mirror 33 via the quarter-wave plate 34. The reflected light flux enters the PBS 32 again via the quarter wavelength plate 34. The light beam incident on the PBS 32 is polarized and converted to a P-polarized component by passing through the quarter-wave plate 34 twice. Therefore, the light passes through the polarization separation unit 31 of the PBS 32 and proceeds to the left.

  The transmitted light beam traveling leftward is emitted from the PBS 32, travels leftward, and is projected to the outside through the diaphragm 35. Thereby, the optical image by the liquid crystal panel 23 is projected toward a screen or the like. By using the projection optical system in which the refractive lens is omitted in this way, chromatic aberration can be suppressed while being compact.

  The configuration of the second housing 12 (pedestal) will be described. The second casing 12 is arranged on the installation surface 200 so that the installation surface (lower side in FIG. 2) of the installation unit 13 and the projector installation surface 200 are in surface contact. The projector arrangement surface 200 is a top plate such as a desk or table, a wall, a ceiling, a pillar, or the like. An opening H is provided on the installation surface of the installation unit 13, and at least a part of the lower surface 21 a of the metal substrate 21 is exposed to the arrangement surface 200 side.

  A gap is formed between the lower surface 21 a of the metal substrate 21 and the arrangement surface 200 so as to ensure an air layer in a state where the projector 100 is arranged on the arrangement surface 200. Further, the installation unit 13 also serves as a guard member as follows when adjusting the orientation of the first housing 11 on the second housing 12. When the orientation of the first housing 11 is changed on the second housing 12, the angle formed by the metal substrate 21 fixed to the first housing 11 and the installation surface of the installation unit 13 changes. . If this angle increases, the lower surface 21a of the metal substrate 21 may come into contact with the installation surface 200. Therefore, the lower surface 21a is arranged so that the lower surface 21a touches the installation part 13 before the installation surface 200. Contact with the installation surface 200 is prevented.

  In the projector 100, the LED 22 generates heat when a large current is passed. The generated heat is transmitted to the metal substrate 21 and radiated from the lower surface 21a of the metal substrate 21 to the air layer. For this reason, the portion immediately below the LED 22 in the metal substrate 21 has the highest temperature, but since this portion is in the space surrounded by the second casing 12 and the arrangement surface 200, a person accidentally touches the high temperature portion. There is no fear. Further, since the arrangement surface 200 is not directly exposed to a high temperature, an increase in the temperature of the arrangement surface 200 can be suppressed.

According to the first embodiment described above, the following operational effects can be obtained.
(1) Since the air layer is secured between the metal substrate 21 on which the LED 22 is mounted and the arrangement surface 200 in a state where the projector 100 is arranged on the arrangement surface 200, the arrangement surface 200 is directly heated to a high temperature. The generated heat can be reliably radiated to the air layer without being exposed to air. Accordingly, it is not necessary to add a metal heat radiating member such as a heat sink or a fin, a fan or a Peltier element, and the projector 100 with a small size and power saving can be obtained.

(2) Since the portion immediately below the LED 22 that is the highest temperature in the metal substrate 21 is in the space surrounded by the second casing 12 and the arrangement surface 200, a person does not touch it accidentally and feels uncomfortable. .

(3) Since the orientation of the first casing 11 can be adjusted on the second casing 12 by a mechanism similar to the spherical joint, even after the projector 100 is fixed to the arrangement surface 200 The traveling direction of light emitted from the LED 22 (projection direction by the projector 100) can be adjusted. In addition, since the installation portion 13 of the second housing 12 serves as a guard member, the metal substrate 21 is protected from contact with the arrangement surface 200 when the orientation of the first housing 11 is adjusted. it can.

(4) Since the center line (optical axis Ax) of the light beam emitted from the LED 22 is substantially perpendicular to the arrangement surface 200 and this light beam is bent and projected by the PBS 32, the optical axis Ax2 after bending And the arrangement surface 200 can be widened. As a result, the height of the projection optical axis can be gained, and a part of the projection light beam can be prevented from being scattered on the arrangement surface 200.

  You may comprise the installation part 13 of the 2nd housing | casing 12 with a magnetic material, or it may comprise an adsorption | suction action like a suction cup.

  By providing the opening H on the installation surface of the installation unit 13, heat can be easily radiated from the lower surface 21 a of the metal substrate 21 to the air layer, while the lower surface 21 a of the metal substrate 21 does not contact the installation surface 200. The edge serves as a guard member. Instead, the opening H may be configured to be covered with a mesh member, or the opening H may be configured with a slit.

(Second embodiment)
FIG. 3 is a cross-sectional view of a liquid crystal projector 100B according to the second embodiment of the present invention. In FIG. 3, the same members as those of the configuration of FIG. The projector 100 </ b> B includes a first housing 51 that houses the optical block, and a second housing 52 that serves as a pedestal for the first housing 51.

  The second casing 52 (pedestal) is disposed on the placement surface 200 so that the installation portion 53 and the projector placement surface 200 are in surface contact. The installation portion 53 is provided with a screw hole, and the second casing 52 can be fixed to the arrangement surface 200 using the screw B.

  The first housing 51 (optical block) is configured to be slidable along the inner surface of the second housing 52 in the direction of the optical axis Ax in FIG. When the first casing 51 (optical block) is slid to the lowest position, the lower surface 21 a of the metal substrate 21 is configured to come into surface contact with the arrangement surface 200. At this time, the protrusion C provided on the inner surface of the second casing 52 is click-engaged with the groove g1 provided on the outer surface of the first casing 51, whereby the second casing 52 is provided. Holds the first housing 51. Thus, when the projector 100b is disposed on the metal arrangement surface 200, heat can be directly radiated from the metal substrate 21 to the arrangement surface 200.

  When the first casing 51 (optical block) is slid upward from the state of FIG. 3, the protrusion C that is click-engaged with the groove g1 is disengaged from the groove g1, and as shown in FIG. 4, the groove g1 It click-engages with a groove g2 provided further downward. FIG. 4 is a cross-sectional view of the projector 100B in which the second casing 52 holds the first casing 51 so as to secure an air layer between the metal substrate 21 and the arrangement surface 200. Thus, when it is desired to radiate heat from the metal substrate 21 to the air layer, a heat radiating space can be easily secured without using a tool.

According to the second embodiment described above, the following operational effects can be obtained.
(1) With the projector 100b arranged on the arrangement surface 200, an air layer is secured between the metal substrate 21 on which the LED 22 is mounted and the arrangement surface 200 (FIG. 4). The generated heat can be reliably radiated to the air layer without directly exposing 200 to a high temperature. As in the first embodiment, a small and power-saving projector 100b can be obtained.

(2) In the case where heat can be directly radiated to the arrangement surface 200, the lower surface 21a of the metal substrate 21 is in surface contact with the arrangement surface 200 (FIG. 3), so that the generated heat is efficiently disposed. Heat can be released to 200.

(3) The state changes of (1) and (2) are performed only by sliding the first casing 51 (optical block) along the inner surface of the second casing 52 in the direction of the optical axis Ax. Therefore, the projector 100b that is easy to use can be obtained.

(4) As in the first embodiment, since the portion immediately below the LED 22 that is the highest temperature in the metal substrate 21 is in the space surrounded by the second casing 52 and the arrangement surface 200, a person mistakenly There is no discomfort when touching.

(5) As in the first embodiment, the center line (optical axis Ax) of the light beam emitted from the LED 22 is set to be substantially perpendicular to the arrangement surface 200, and this light beam is bent by the PBS 32 and projected. As a result, the height of the projection optical axis can be increased, and a part of the projection light beam can be prevented from being scattered on the arrangement surface 200.

  Another groove portion may be provided further below the groove portion g2 on the outer surface of the first housing 51. Thereby, the space | gap between the metal substrate 21 and the arrangement | positioning surface 200 can be expanded further, and the thermal radiation amount can be raised. By selecting the groove portion to be click-engaged with the protrusion C, a gap corresponding to the required heat radiation amount can be secured.

  In the case of the configuration of FIG. 3, an elastic sheet having a high thermal conductivity may be sandwiched between the lower surface 2 a of the metal substrate 21 and the arrangement surface 200. According to this, the unevenness | corrugation of the arrangement | positioning surface 200 can be absorbed with an elastic sheet, adhesiveness can be improved, and heat conduction efficiency can be improved.

(Third embodiment)
FIG. 5 is a front view of a liquid crystal projector 100C according to the third embodiment, and FIG. 6 is a sectional view taken along line AA ′. 5 and 6, the same members as those in FIGS. 1 and 2 that describe the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Similar to the first embodiment, the projector 100 </ b> C includes a first housing 11 that houses the optical block and a second housing 12 that serves as a base for the first housing 11.

  The configuration of the optical block in the first housing 11 will be described. Compared with the first embodiment, the light beam emitted from the LED 22 is bent using the reflection mirror 62, the light beam emitted from the LED 22 is guided to the reflection mirror 62 via the light collecting member 61, and the liquid crystal panel 23 is different from the arrangement position of the projection optical system using the refractive lens 63.

  The light beam emitted upward from the LED 22 in FIG. 6 is collected by the light collecting member 61 and guided to the reflection mirror 62, reflected by the reflection mirror 62, and travels to the left. The condensing member 61 is, for example, formed of a Fresnel lens using a resin material, and also has a function of separating and blocking the space in the optical block into the LED 22 side and the liquid crystal panel 23 side.

  The reflected light beam that has traveled to the left passes through the liquid crystal panel 23, travels further to the left, and is projected to the outside through the refractive lens 63 and the diaphragm 35. Thereby, the optical image by the liquid crystal panel 23 is projected toward a screen or the like.

  According to the third embodiment described above, since the space between the LED 22 side and the liquid crystal panel 23 side is separated and cut off in the optical block, in addition to the same effect as the first embodiment, it occurs in the LED 22. It is possible to make it difficult for heat to be transmitted to other members (particularly, the liquid crystal panel 23) constituting the optical block.

  In the above description, the transmissive liquid crystal panel 23 is exemplified as the optical image forming element, but a reflective liquid crystal (LCOS) may be used instead of the transmissive liquid crystal panel.

  Moreover, although the example which uses LED22 as a light source of a projector was demonstrated, not only a projector but the other light irradiation apparatus which uses LED as a light source, for example, the camera provided with the illuminating device by LED, the illuminating device by LED, AF by LED The present invention can also be applied to a camera equipped with an auxiliary light source.

  Although the LED has been described as an example of the light emitting element, the present invention can also be applied to a light irradiation apparatus using an LD (semiconductor laser).

  Correspondence between each component in the claims and each component in the best mode for carrying out the invention will be described. The light irradiation device is configured by, for example, a projector 100 (100B / 100C). For example, the lower surface 21a corresponds to the surface facing the installation surface. The mounting board is constituted by, for example, a metal board 21. The casing is constituted by, for example, a first casing 11 (51) and a second casing 12 (52). The optical path changing member is configured by, for example, PBS 32 (reflection mirror 62). In addition, the above description is an example to the last, and when interpreting invention, it is not limited to the correspondence of the component of said embodiment and the component of this invention at all.

1 is a front view of a liquid crystal projector according to a first embodiment of the present invention. It is sectional drawing of FIG. It is sectional drawing of the liquid crystal projector by 2nd embodiment. It is sectional drawing of the liquid crystal projector by 2nd embodiment. It is a front view of the liquid-crystal projector by 3rd embodiment. It is sectional drawing of FIG.

Explanation of symbols

11 (51) ... 1st housing | casing 11s ... Base contact part 12 (52) ... 2nd housing | casing 12s ... Optical system receiving part 13 (53) ... Installation part 21 ... Metal substrate 22 ... LED
23 ... Liquid crystal panel 32 ... PBS
DESCRIPTION OF SYMBOLS 100 (100B, 100C) ... Projector 200 ... Arrangement surface Ax, Ax2 ... Optical axis C ... Projection g1, g2 ... Groove H ... Opening

Claims (3)

In a light irradiation device that emits light from a light emitting element,
A metal mounting board on which the light emitting element is mounted on the back surface of the surface facing the installation surface, and disposed substantially parallel to the installation surface of the light irradiation device,
A housing that covers the mounting substrate so that at least a part of a surface facing the installation surface is exposed ;
The housing provides a gap between the mounting substrate and the installation surface,
The light irradiation apparatus , wherein the mounting substrate is configured to be movable with respect to the casing so that a distance between the facing surface and the installation surface is variable . In the light irradiation apparatus of Claim 1,
The light irradiation apparatus , wherein the mounting substrate is configured to be movable with respect to the housing so that an inclination angle of the facing surface with respect to the installation surface is variable . The light irradiation device according to claim 1 or 2,
  A light image forming element that modulates light from the light irradiation device to form a light image;
  An optical path changing member for changing the optical path;
  A projector apparatus comprising: a projection optical system that projects a light image formed by the light image forming element.

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