JP2016057601A - Projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the illuminance from decreasing even when devitrification is generated in a light-emitting part.SOLUTION: A projector device according to an aspect of the present disclosure comprises a light-emitting tube 3 made of quartz glass, a concave reflection mirror 124 having the light-emitting tube 3 placed therein, and an optical unit 209 for projecting an image by using light emitted from the concave reflection mirror 124. The light-emitting tube 3 is arranged so that a pair of electrodes face a vertical direction (Z axis). Even though the light-emitting tube 3 is in a vertical lighting arrangement, the optical unit 209 is configured such that an area of a projected image becomes a horizontally long rectangular shape. The light-emitting tube 3 includes at least mercury inside and has a light-emitting part 6 in which the pair of electrodes are arranged so as to face each other and a pair of sealing parts 11 and 13 which extend from the light-emitting part 6 in directions opposite from each other.SELECTED DRAWING: Figure 7

Description

  The present application relates to a projector apparatus.

  Conventionally, high-pressure discharge lamps, particularly high-pressure mercury lamps, have been used as projector light sources. The high-pressure mercury lamp includes a light emitting tube made of quartz glass having a light emitting portion in which a discharge space is formed and a pair of sealing portions extending from the light emitting portion in opposite directions. In the light emitting part, the pair of electrodes are located on the central axis in the longitudinal direction of the arc tube and are arranged to face each other. Therefore, the central axis in the longitudinal direction of the pair of electrodes and the central axis in the longitudinal direction of the arc tube substantially coincide with each other. Such an arc tube is arranged in the light source unit so that the optical axis in the reflecting mirror and the central axis in the longitudinal direction of the electrode substantially coincide. The light source unit is incorporated in the projector apparatus in such a state that the central axis in the longitudinal direction of the electrode in the light emitting section is substantially horizontal. When the axis (optical axis) of light emitted from the projector device is substantially horizontal, the light emitted from the projector device is projected so as to form a horizontally-long rectangular image on a vertically erected screen. (See Patent Document 1). The reason for projecting a horizontally long rectangular image is to comply with the standard.

  Such a projector device may be used in a vertical position (see Patent Document 2). This is because a vertically long rectangular image is used by placing the projector vertically. By arranging a plurality of vertically arranged projectors side by side, the vertically long rectangular images can be connected to realize a large screen.

JP-A-6-235975 JP 2005-62590 A

  There is a need to extend the lamp life in projector devices.

  The embodiment of the present disclosure can suppress a decrease in illumination maintenance rate due to devitrification of the arc tube.

  The projector device according to the present disclosure includes a light emitting unit in which at least mercury is enclosed and a pair of electrodes are disposed so as to face each other, and a pair of sealing units extending from the light emitting unit in opposite directions to each other. A quartz glass arc tube, a concave reflecting mirror in which the arc tube is disposed, and an optical unit for projecting an image using light emitted from the concave reflecting mirror, The pair of electrodes are arranged so as to face in the vertical direction, and the optical unit is configured such that a region of an image to be projected is a horizontally long rectangle.

  According to the projector device according to the present disclosure, the position of devitrification generated in the arc tube can be removed from the effective range from which light is extracted. Even if devitrification occurs in the vicinity of the sealing portion of the light emitting portion, such devitrification does not affect the emitted light. According to the present disclosure, it is possible to suppress a decrease in the illuminance maintenance rate.

Sectional drawing which shows typically how to arrange | position the high-pressure discharge lamp 1 in a well-known projector apparatus, and the angle range of the light radiated | emitted from the high-pressure discharge lamp 1 Sectional drawing which shows a mode that the light radiated | emitted from the high voltage | pressure discharge lamp 1 of horizontal lighting arrangement | positioning is reflected by the concave reflecting mirror 124 Sectional drawing which shows a mode that the light radiated | emitted from the high pressure discharge lamp 1 of a vertical lighting arrangement | positioning is reflected by the concave reflecting mirror 124 The figure (left side) corresponding to the photograph of the light emission part in the high pressure discharge lamp of horizontal lighting arrangement, and the figure (right side) which shows the position of the devitrification part 100 in a light emission part The figure corresponding to the photograph of the light emission part in the high pressure discharge lamp of the vertical lighting arrangement (left side), and the figure showing the position of the devitrification part 100 in the light emission part (right side) The figure which shows typically the case where the angle (alpha) which the central axis (J1 axis) and the vertical direction (Z axis) of the longitudinal direction of an electrode form is not 0 degree. The perspective view which shows a part of internal structure of the projector 201 which concerns on embodiment of this indication. Sectional drawing which shows typically the example of the internal structure of the optical unit 209 in the projector 201 which concerns on embodiment of this indication. The perspective view which shows typically the example of the internal structure of the optical unit 209 in the projector 201 which concerns on embodiment of this indication. Side view showing the configuration of the high-pressure discharge lamp 1 according to Embodiment 1 of the present disclosure. The figure which expands and shows a part of electrodes 7 and 9 Sectional drawing which shows the structure of the light source unit 110 which concerns on embodiment of this indication. Block diagram showing a configuration example of the power supply unit 207 Graph showing an example of the relationship between the power and voltage of a high-pressure discharge lamp The figure for explaining the temporal change of the devitrification area that affects the illuminance in the horizontal lighting arrangement Diagram for explaining temporal change of devitrification area that affects illuminance in vertical lighting arrangement The figure which shows the result of having measured the time change of the illumination intensity maintenance factor of three samples about each of a vertical lighting arrangement and a horizontal lighting arrangement

  Prior to describing specific embodiments of the present disclosure, the knowledge forming the basis of the present disclosure will be described.

  In a known projector device, the high-pressure discharge lamp is lit with the central axis in the longitudinal direction of the electrode being substantially horizontal. It is known that the surface temperature of the arc tube reaches close to 1000 ° C. during lighting. As a result, in the arc tube made of quartz glass, the upper center portion of the light emitting portion, which is located above the vertical direction in particular, becomes clouded. When the arc tube becomes cloudy, the light transmittance at that portion is significantly reduced. Such white turbidity of quartz glass is a phenomenon called “devitrification”, and is caused by crystallization of amorphous. The devitrification blocks light emitted from the discharge space, so that the luminous flux is reduced and the illuminance maintenance rate of the high-pressure discharge lamp is lowered. In order to extend the life of the lamp, it has been required to suppress the occurrence of devitrification.

  The inventor of the present application has found that even if quartz glass becomes clouded due to devitrification, it is possible to suppress a decrease in the illuminance maintenance rate of the high-pressure discharge lamp by adjusting the position of the clouding portion. The present disclosure has been conceived.

  FIG. 1 schematically shows an arrangement example of a high-pressure discharge lamp 1 in a known projector device and an angular range of light emitted from the high-pressure discharge lamp 1. In FIG. 1, for easy understanding, a coordinate axis composed of an X axis, a Y axis, and a Z axis that are orthogonal to each other is shown. The XY plane is parallel to the horizontal plane, and the Z axis is parallel to the vertical direction. In the present specification, the central axis in the longitudinal direction of the electrode of the high-pressure discharge lamp 1 may be referred to as “J1 axis”. An arrow D in FIG. 1 indicates a direction inclined by θ with respect to the J1 axis.

  The high-pressure discharge lamp 1 shown in FIG. 1 is arranged so that the central axis J1 axis in the longitudinal direction of the electrode is parallel to the horizontal plane (XY plane) and orthogonal to the vertical direction (Z axis). . Such an arrangement is referred to as a “horizontal lighting arrangement” in this specification. The arrangement of the high-pressure discharge lamp 1 in the conventional projector apparatus is a horizontal lighting arrangement.

  The intensity of light emitted from the high-pressure discharge lamp 1 varies depending on the angle θ with respect to the central axis (J1 axis) in the longitudinal direction of the electrode. Generally, the highest intensity is exhibited in a direction orthogonal to the J1 axis, that is, in a direction where the angle θ is about 90 °. In addition, the angle θ is the lowest in the direction close to 0 ° and 180 °. When used in combination with a reflector (reflecting mirror) whose reflecting surface is a parabolic reflecting surface, among the light emitted from the high-pressure discharge lamp 1, the light reflected by the concave reflecting surface is relative to the J1 axis. Proceed in parallel. This light is used for image projection. FIG. 1 schematically shows an effective range 350 indicating an angle at which light emitted from the light emitting unit can be extracted and used for image projection. This effective range 350 extends axisymmetrically around the J1 axis. The effective range 350 schematically illustrated in FIG. 1 is a range in which the angle θ is, for example, not less than 25 ° and not more than 155 °. The light distribution characteristics of the high-pressure discharge lamp 1 depend on the structure and shape of the arc tube, the shape and size of the electrodes, the distance between the electrodes, and the like. For this reason, the lower limit and the upper limit of the angle that define the effective range 350 may vary. The same can be said even when the reflecting surface is various reflecting surfaces such as an elliptical reflecting surface.

  In the quartz glass arc tube of the high-pressure discharge lamp 1, when the above-described devitrification occurs at the end of the lamp life, the upper central portion of the light emitting portion becomes cloudy. Hereinafter, with reference to FIG. 2A and FIG. 2B, the site | part which a cloudiness produces is demonstrated in detail.

  FIG. 2A shows a state in which the light emitted from the high-pressure discharge lamp 1 in the horizontal lighting arrangement is reflected by the concave reflecting mirror 124. In the high-pressure discharge lamp 1 arranged horizontally, the devitrification part 100 is generated in the upper center part of the light emitting part and becomes white turbid when the temperature becomes high. Then, the light emitted in the direction in which the light intensity is highest is affected by the devitrification unit 100. The local decrease in the light intensity caused by the devitrification part 100 in this way causes a decrease in the luminous flux used for image projection.

  The present inventor has thought that by appropriately adjusting the direction (arrangement) of the high-pressure discharge lamp 1, it is possible to avoid a decrease in light intensity and luminous flux due to white turbidity of the devitrification portion 100. That is, the position where the devitrification part 100 is formed is removed from the direction in which the light intensity is highest by directing the central axis (J1 axis) in the longitudinal direction of the electrode of the high-pressure discharge lamp 1 in the vertical direction (Z-axis). Found that it would be possible. A typical example of such an arrangement of the high-pressure discharge lamp 1 is an arrangement in which the central axis (J1 axis) in the longitudinal direction of the electrode coincides with the vertical direction (Z-axis). Such an arrangement can be referred to as a “vertical lighting arrangement” in contrast to the conventional “horizontal lighting arrangement”. For reasons that will be described later, the center axis (J1 axis) in the longitudinal direction of the electrode does not have to be completely parallel to the vertical direction (Z axis).

  FIG. 2B shows a state in which the light emitted from the high-pressure discharge lamp 1 in the vertical lighting arrangement is reflected by the concave reflecting mirror 124. In this example, the central axis (J1 axis) in the longitudinal direction of the electrode is parallel to the vertical direction (Z axis). In the case of the vertical lighting arrangement, according to the experiment of the present inventor, it has been found that the devitrification part 100 is formed at the upper central part of the light emitting part in the arc tube as shown in FIG. 2B. Even if the devitrification part 100 is formed at such a position and white turbidity occurs, the emitted light is hardly blocked. As a result, the illuminance maintenance rate of the high-pressure discharge lamp 1 is unlikely to decrease. It has been found that by adopting the vertical lighting arrangement, the life of the lamp can be extended from 1.5 times to about 2 times as compared with the case of the horizontal lighting arrangement.

  FIG. 3A is a diagram (left side) corresponding to a photograph of a light emitting part in a high-pressure discharge lamp arranged horizontally, and a diagram (right side) showing the position of the devitrification part 100 in the light emitting part. This figure shows the devitrification part 100 when the round light emission part of the high pressure discharge lamp 1 is seen from the direction of arrow D in FIG. 2A. It can be seen that the devitrification part 100 extends to the center of the light emitting part.

  FIG. 3B is a diagram (left side) corresponding to a photograph of a light emitting part in a high-pressure discharge lamp arranged vertically, and a figure (right side) showing the position of the devitrification part 100 in the light emitting part. This figure shows the devitrification part 100 when the round light emission part of the high pressure discharge lamp 1 is seen from the direction of arrow D in FIG. 2A. The devitrification part 100 is generated at a position closer to the end than the center of the light emitting part. When the devitrification part 100 is formed in the site | part as shown to FIG. 3B, it can fully suppress that light is interrupted by the devitrification part 100. FIG.

  FIG. 4 is a diagram schematically showing an example in which the angle α formed by the central axis (J1 axis) in the longitudinal direction of the electrode and the vertical direction (Z axis) is not 0 °. When the angle α increases, the devitrification part 100 formed on the light emitting part may block light in the effective range 350. According to the study of the present inventor, if the angle α formed by the central axis (J1 axis) in the longitudinal direction of the electrode and the vertical direction (Z axis) is 30 ° or less, the devitrification part 100 can reduce the effective range 350. It is possible to sufficiently suppress the light from being blocked. Further, it was found that when the angle α is 20 ° or less, the devitrification part 100 hardly blocks light in the effective range 350. Therefore, in this specification, the “vertical lighting arrangement” means an arrangement in which the angle formed by the central axis (J1 axis) in the longitudinal direction of the electrode and the vertical direction (Z axis) is 30 ° or less. However, even if the angle formed by the central axis (J1 axis) in the longitudinal direction of the electrode and the vertical direction (Z axis) exceeds 30 °, the effect of devitrification is sufficient depending on the structure of the high-pressure discharge lamp. It may be possible to lower it. If the arc tube is arranged so that the pair of electrodes face the direction closer to the vertical direction than the horizontal direction, the influence of devitrification can be reduced. In the present specification, the fact that the pair of electrodes face the direction closer to the vertical direction than the horizontal direction is expressed as “the pair of electrodes face the vertical direction”. In other words, “a pair of electrodes face the vertical direction” means that the angle formed by the central axis (J1 axis) in the longitudinal direction of the electrodes and the vertical direction (Z axis) is less than 45 °.

  According to a certain aspect, the projector device of the present disclosure completed from the above considerations, according to a certain aspect, includes a quartz glass arc tube, a concave reflector in which the arc tube is disposed, and light emitted from the concave reflector. And an optical unit for projecting an image. The arc tube has a pair of electrodes arranged in the vertical direction (that is, α <45 °), and typically realizes a “vertical lighting arrangement” (α ≦ 30 °). Further, the optical unit is configured such that the area of the image to be projected becomes a horizontally long rectangle even though the arc tube is in the vertical lighting arrangement. The arc tube has a light emitting part in which at least mercury is sealed and a pair of electrodes are arranged to face each other, and a pair of sealing parts extending from the light emitting part in opposite directions. ing. The structure itself of the arc tube is not particularly limited, and may have various known structures.

  In one embodiment, the concave reflecting mirror is arranged so that the optical axis is aligned with the longitudinal central axis of the pair of electrodes. The relationship between the optical axis of the reflecting mirror and the central axis in the longitudinal direction of the pair of electrodes does not have to be “parallel” in a strict sense. In the present specification, “alignment” of one axis with another axis is defined to mean that the angle formed by both axes is 30 ° or less.

  In one embodiment, the angle between the longitudinal center axis of the pair of electrodes and the vertical direction is 20 ° or less. When this angle exceeds 20 °, the portion where the devitrification part 100 is formed shifts to a region that blocks the light beam.

  In one embodiment, the optical unit includes at least one spatial light modulation element that forms an image using light emitted from the concave reflecting mirror, and a lens that projects an image formed by the spatial light modulation element (hereinafter, referred to as “light emitting element”). (Referred to as a “projection lens”). When the projector device according to the present disclosure is used, the long-side direction of the region of the image projected on the object such as the screen coincides with the horizontal direction. That is, a horizontally long rectangular image according to the standard can be formed on the screen. On the other hand, the pair of electrodes of the arc tube is oriented in the vertical direction (preferably arranged in a vertically lit manner). Therefore, when considering a plane including both the optical axis of the projection lens and the central axis in the longitudinal direction of the pair of electrodes of the arc tube, this plane intersects the long side direction of the projected image area (typically Are orthogonal).

  Here, for comparison, consider a case where a conventional projector apparatus is rotated 90 ° around the optical axis of the projection lens to temporarily change the light emitting tube in the horizontal lighting arrangement to the “vertical lighting arrangement”. In this case, the area of the projected image is a so-called “vertically long rectangle”. Therefore, the plane including both the optical axis of the projection lens and the central axis in the longitudinal direction of the pair of electrodes of the arc tube does not intersect the long side direction of the projected image area and is in a parallel relationship. .

  A typical example of the spatial light modulator is a transmissive liquid crystal panel, a reflective liquid crystal panel, or a digital mirror device. However, the spatial light modulation element is not limited to these examples. Further, the number of spatial light modulation elements used is not limited to one. The light emitted from the high-pressure discharge lamp may be divided for each color, and a spatial light modulation element for forming a different image for each color may be placed on the divided optical path. Different images for each color thus formed can be combined to form a color image and projected onto a screen or other object.

  According to the projector device according to the present disclosure, the position of devitrification generated in the arc tube can be removed from the region where the light intensity in the light emitting unit is relatively high. Specifically, devitrification occurs in the vicinity of the sealing portion of the light emitting portion. The light radiated from the discharge space of the arc tube is directly or directly reflected by the inner surface of the reflecting mirror and emitted from the opening of the reflecting mirror. At that time, the radiated light from the discharge space is emitted in all directions of 360 ° except for the back of the electrode, with the center of the light-emitting portion becoming a luminescent center in a pseudo manner. The reason for “except for the back of the electrode” is that the electrode is shaded to block the emitted light. Therefore, even if devitrification occurs in the vicinity of the sealing portion of the light emitting portion, the vicinity of the sealing portion is located behind the electrode, and thus does not contribute to the light emitted from the reflecting mirror. For this reason, the fall of an illumination intensity maintenance factor can be suppressed.

  According to the configuration of the projector device according to an embodiment of the present disclosure, the range in which devitrification occurs due to the inclination of the central axis of the pair of electrodes in the longitudinal direction with respect to the vertical direction is within 20 ° Can be sufficiently suppressed in the vicinity.

(Embodiment 1)
An embodiment of the present disclosure is a projector device including a high-pressure discharge lamp that is vertically lit. Hereinafter, more specific embodiments of the present disclosure will be described.

<Projector device>
First, a schematic configuration of the projector 201 according to the embodiment of the present disclosure will be described. FIG. 5 is a perspective view showing a part of the internal structure of the projector 201 according to the embodiment of the present disclosure. FIG. 5 is a diagram in which the projector 201 is viewed obliquely from the bottom side for the sake of easy understanding. FIG. 5 shows the same Z-axis as in FIG. 2B. As described above, the horizontal plane is parallel to the XY plane, and the Z axis is parallel to the vertical direction. Light rays from the projector 201 are emitted in a direction perpendicular to the Z axis (referred to as the X axis direction).

  The projector 201 is a front projection type liquid crystal projector. The projector 201 includes components such as a light source unit 110 having a high-pressure discharge lamp arranged in a vertically lit state, a power supply unit 207 including a drive circuit for lighting the high-pressure discharge lamp, a control unit 215, and an optical unit 209. 213 is provided inside. The optical unit 209 includes a projection lens 219, a condenser lens, a transmissive color liquid crystal display panel, and a drive motor, and is arranged so that the lens 219 protrudes outside the case 213.

  The power supply unit 207 converts an AC voltage (for example, a voltage of AC 100 to 120 V for home use) into a predetermined DC voltage and supplies it to the drive circuit and control unit 215. The control unit 215 includes a substrate disposed in the vicinity of the optical unit 209 and a plurality of electronic / electrical components mounted on the substrate.

  The control unit 215 drives a color liquid crystal display panel based on an image signal input from the outside to display a color image. In addition, a focusing motor and a zooming operation are executed by controlling a driving motor arranged inside the optical unit 209.

  The light emitted from the light source unit 110 is converged by a condensing lens disposed inside the optical unit 209 and passes through a color liquid crystal display panel disposed in the middle of the optical path. As a result, an image formed on the color liquid crystal display panel is projected onto a screen (not shown) via an optical system such as a lens 219. As described above, the optical unit 209 modulates the light emitted from the light source unit 110 to form an image for display.

  In the present embodiment, the optical unit 209 has a liquid crystal display plate on the optical path, but the configuration of the optical unit 209 is not limited to such an example. The image to be displayed may be formed by a processing apparatus provided with a digital mirror device, for example.

  FIG. 6 is a cross-sectional view schematically showing an example of an optical path in the projector 201.

  In the example shown in FIG. 6, light emitted from the light source unit 110 to the upper side in the vertical direction (Z-axis) is collimated by a lens (not shown) arranged inside the optical unit 209 and arranged in the middle of the optical path. The light is branched for each color by the mirrors 60, 61, 62, 64 and 65. For simplicity, illustration of optical elements such as lenses and various filters is omitted in FIG.

  The mirror 60 and the mirror 62 are dichroic mirrors configured to selectively reflect red (R) and green (G) light, respectively. In this example, the red light selectively reflected by the mirror 60 is reflected by another mirror 61 and travels toward the dichroic prism 63. Before the red light enters the dichroic prism 63, the red light passes through the transmissive first liquid crystal panel 67 that functions as a spatial light modulation element, and forms a luminance distribution of a red image. The light transmitted through the mirror 60 includes green and blue components. Of this light, the green light selectively reflected by the mirror 62 passes through a transmissive second liquid crystal panel 68 that functions as a spatial light modulation element to form a luminance distribution of a green image. The blue light that has passed through the mirror 60 is reflected by the mirror 64, is further reflected by another mirror 65, and travels toward the dichroic prism 63. Before the blue light enters the dichroic prism 63, the blue light passes through the transmissive third liquid crystal panel 69 functioning as a spatial light modulation element, and forms a luminance distribution of a blue image.

  The different images for each color formed by the three spatial light modulators are combined with a color image inside the dichroic prism 63. Light rays constituting the color image are emitted through the projection lens 219, and a horizontally long rectangular image is displayed on an object such as a screen (not shown).

  FIG. 7 is a perspective view schematically showing the optical path shown in FIG. 6 and the arrangement of the mirrors 60, 61, 62, 64, 65 and the dichroic prism 63 placed on the optical path. FIG. 7 shows a horizontally-long rectangular image display area 300 formed by light rays emitted from the projector device. Although not apparent in FIG. 7, the image display area 300 is projected onto a screen or other object (not shown). The image display area 300 is enlarged at a desired magnification by the projection lens 219. The image display area 300 has a horizontal size (width W) in the horizontal direction (Y-axis direction) and a vertical size (height H) in the vertical direction (Z-axis direction). The horizontal size: vertical size (= W: H) can be set to a ratio (aspect ratio) such as 4: 3 or 16: 9, for example. In the projector device according to the embodiment of the present disclosure, the direction of each optical element in the optical unit 209 is set so that a horizontally-long rectangular image having a horizontal size (width W) larger than the vertical size (height H) is obtained. ing.

  As described above, the internal configuration of the optical unit 209 is not limited to this example. The image to be displayed may be formed by a processing apparatus equipped with a digital mirror device. Further, a rotating three-color filter board may be disposed on the optical path, and images of different colors may be projected in a field sequential manner, thereby forming a color image. The important point is that the optical unit 209 is configured to project a horizontally-long rectangular image using light emitted from the arc tube in which the pair of electrodes are oriented in the vertical direction.

  In the example shown in FIGS. 5, 6, and 7, the light source unit 110 is arranged so that light travels upward in the vertical direction (Z axis), but the direction of the light source unit 110 is not limited to this example. . If the arrangement in which the pair of electrodes are oriented in the vertical direction is realized, the light source unit 110 may be arranged so as to emit light downward in the vertical direction (Z axis).

  According to the embodiment of the present disclosure, the light emitted from the arc tube travels in the vertical direction (Z-axis), so the vertical size of the projector device is relatively enlarged. However, the external shape of the projector device is not limited to the form described with reference to FIGS. 5 to 7, that is, the form (vertical type) having the external shape in which the size in the vertical direction is larger than the size in the other direction. . A so-called “horizontal type” may be used in which the vertical size is smaller than the size in other directions. Also, by arranging a mirror that reflects the light emitted from the arc tube in a direction parallel to the XY plane, that is, the angle formed by the central axis in the longitudinal direction of the electrode and the normal direction of the reflecting surface of the mirror is A “horizontal type” can be realized by arranging the mirrors at about 45 °. In any case, the external shape of the projector device is not limited to a specific shape such as a vertical type or a horizontal type.

<High pressure discharge lamp>
FIG. 8 is a side view illustrating a configuration example of the high-pressure discharge lamp 1 according to the first embodiment of the present disclosure.

  The “high pressure discharge lamp” is sometimes called a high intensity discharge lamp (HID). The high-pressure discharge lamp includes a lamp that operates at a high pressure such as a metal halide lamp and an ultra-high pressure mercury lamp. The pressure in the arc tube of the high-pressure discharge lamp can show a high value such as several to over 100 atm depending on the type during operation. The high-pressure discharge lamp 1 in the present embodiment is an ultra-high pressure mercury lamp, but is not limited thereto, and may be another type of high-pressure discharge lamp. The rated power consumption of the high-pressure discharge lamp 1 can be, for example, 100 W to 1 kW. In this embodiment, the rated power consumption is 310 W.

  The high-pressure discharge lamp 1 includes an arc tube 3, a pair of electrodes 7 and 9, a pair of metal foils 23 and 25, a pair of external lead wires 27 and 29, and a trigger wire 51. The electrodes 7 and 9, the metal foils 23 and 25, and the external lead wires 27 and 29 constitute a pair of electrode structures.

<Luminescent tube>
The arc tube 3 is made of a translucent material such as quartz glass. The arc tube 3 includes a light emitting part 6 having a discharge space 5 formed therein, and sealing parts 11 and 13 extending in two directions away from both sides in the longitudinal direction of the light emitting part 6. The outer shape of the light emitting unit 6 is, for example, a substantially spheroid shape. The external shape of the sealing parts 11 and 13 is cylindrical. The substantially spheroidal shape of the light emitting part 6 and the cylindrical shape of the sealing parts 11 and 13 have a common central axis J1.

Inside the discharge space 5, mercury, which is a luminescent material, a rare gas such as argon, krypton, and xenon that functions as a starting aid, iodine, bromine, and the like necessary to realize a halogen cycle in the discharge space 5 Of halogen gas. The amount of mercury enclosed can be, for example, in the range of 150 mg / cm ³ or more and 650 mg / cm ³ or less. The amount of argon enclosed can be, for example, in the range of 0.01 MPa to 1 MPa in an environment of 25 ° C. The amount of bromine sealed can be, for example, in the range of 1 × 10 ⁻¹⁰ mol / cm ^{3 to} 1 × 10 ⁻³ mol / cm ³ . The amount of bromine sealed can be preferably in the range of 1 × 10 ⁻⁹ mol / cm ³ or more and 1 × 10 ⁻⁵ mol / cm ³ or less.

  The diameter of the sealing portions 11 and 13 of the arc tube 3 can be, for example, 4.0 mm or more and 10 mm or less. The length of the arc tube 3 in the direction of the axis J1 can be, for example, 40 mm or more and 150 mm or less. The light emitting unit 6 may have, for example, a substantially spheroid shape having an outer diameter of 8.0 mm to 40 mm and a maximum inner diameter of 4.0 mm to 20 mm. In this embodiment, the diameter of the sealing portions 11 and 13 of the arc tube 3 is 6.0 mm, the length of the arc tube 3 in the direction of the axis J1 is 60 mm, the outer diameter of the sphere of the light emitting portion 6 is 11.6 mm, and the light emission The maximum inner diameter of the part 6 is 5.4 mm.

<Electrode>
The electrodes 7 and 9 have a rod-like structure. One end of each of the electrodes 7 and 9 is located in the discharge space 5 inside the light emitting unit 6. The electrodes 7 and 9 are arranged to face each other in a state where they are separated by a predetermined distance (hereinafter referred to as “interelectrode distance”) L in the discharge space 5. From the viewpoint of improving the light extraction efficiency of the lamp 1, the interelectrode distance L can be set within a range of 0.5 mm to 2.5 mm, for example. The electrodes 7 and 9 can be made of tungsten, for example.

  FIG. 9 is an enlarged view showing a part of the electrodes 7 and 9. The electrodes 7 and 9 have elongated small-diameter portions 71 and 91, large-diameter portions 72 and 92, and tips 73 and 93. The large diameter portions 72 and 92 are located between the small diameter portions 71 and 91 and the tips 73 and 93, respectively. The electrodes 7 and 9 are formed by melting the tip of the rod-shaped member and a part of the coil in a state where the coil is wound around the tip of the rod-shaped member. The small diameter portions 71 and 91 are portions where the coil of the rod-shaped member is not wound. The large diameter portions 72 and 92 are composed of a portion of the coil that is not melted and a portion of a rod-like member that is located in the center portion thereof. The tips 73 and 93 are melt-formed portions that are connected to the large-diameter portions 72 and 92, respectively. Protrusions 74 and 94 are formed at the tips 73 and 93 due to the halogen cycle during lighting of the lamp 1, respectively. While the lamp 1 is turned on, tungsten constituting the electrodes 7 and 9 evaporates from a part of the electrodes 7 and 9 to become a halogen compound. When the halogen compound returns to the vicinity of the tops of the tips 73 and 93 of the electrodes 7 and 9, it is deposited as tungsten. As a result, protrusions 74 and 94 are formed. The protrusions 74 and 94 are formed in an aging process which is a part of the manufacturing process of the lamp 1. The interelectrode distance L is defined by the distance between the protrusions 74 and 94.

  The tips 73 and 93 of the electrodes 7 and 9 in the present embodiment are substantially hemispherical, but are not limited to such shapes. For example, it may be substantially spherical or substantially conical. The method of forming the tips 73 and 93 is not limited to a method of forming the tips by melting the tips of the rod-shaped members and a part of the coil. For example, a material that has been cut into a substantially hemispherical shape, a substantially spherical shape, or a substantially conical shape may be used.

  When the high-pressure discharge lamp arranged vertically is lit, the temperature of the upper electrode 7 tends to be higher than the temperature of the lower electrode 8. When the temperature is different in this way, the state of wear of each electrode is also different, which affects the life of the lamp. Therefore, when the high-pressure discharge lamp is driven with an AC pulse waveform, the temperature of each of the electrodes 7 and 8 can be adjusted to an extent that does not affect the lamp life by making the drive waveform asymmetry as appropriate.

<Metal foil>
As shown in FIG. 8, the metal foils 23 and 25 are sealed in the sealing portions 11 and 13, respectively. The metal foils 23 and 25 are connected to the electrodes 7 and 9, respectively. The metal foils 23 and 25 can be formed of a metal such as molybdenum, for example. The connection between the metal foils 23 and 25 and the electrodes 7 and 9 can be performed by welding, for example. The length of each of the metal foils 23, 25 in the direction of the axis J1 can be in the range of 10 mm to 50 mm, for example. In this embodiment, this length is 18 mm.

<External lead wire>
One ends of the external lead wires 27 and 29 are connected to the metal foils 23 and 25, respectively. The external lead wires 27 and 29 can be formed of a metal such as molybdenum, for example. The connection between the one end of the external lead wires 27 and 29 and the metal foils 23 and 25 can be performed by, for example, welding. The other ends of the external lead wires 27 and 29 are led out of the sealing portions 11 and 13, respectively, and are electrically connected to a drive circuit in the power supply unit 207 shown in FIG.

<Trigger line>
The trigger line 51 is used to reduce a voltage necessary for starting the lamp 1 (referred to herein as “starting voltage”). The trigger wire 51 can be formed from a linear member having an outer diameter of 0.1 mm to 2.0 mm, for example. The material of the trigger wire 51 can be, for example, a metal having conductivity and heat resistance, such as an alloy of iron and chromium or molybdenum. In the present embodiment, the trigger wire 51 has a circular cross-sectional shape. The cross-sectional shape may be another shape such as a polygon. The trigger line 51 does not have to be formed entirely from a metal line. A part of the shape of the trigger line 51 may be, for example, a band plate shape. In the present disclosure, even a part having a strip-like part in such a part is referred to as a “trigger line”.

<Light source unit>
FIG. 10 is a cross-sectional view illustrating a configuration example of the light source unit 110 according to the embodiment of the present disclosure.

  The light source unit 110 includes the high-pressure discharge lamp 1 in the present embodiment and a concave reflecting mirror 124 that reflects light emitted from the high-pressure discharge lamp 1. The light source unit 110 includes a pair of power supply lines 125 and 127 connected to the external lead wires 27 and 29 at both ends of the high-pressure discharge lamp 1 and connectors 129 and 131 connected to the other ends of the power supply lines 125 and 127, respectively. And connected to the power supply through. The power supply lines 125 and 127 are conductive wires such as nickel wires connected to the external lead wires 27 and 29 (portions 129 and 131 side portions) in which a conductive core material is covered with an insulating coating material. The part which consists of. The power supply lines 125 and 127 are connected to the external lead wires 27 and 29 via connection sleeves 187 and 189, respectively. The reflecting mirror 124 includes a base material 182 having a concave shape and a reflecting surface 181 formed on the base material 182 on the front surface side of the reflecting mirror 124. The reflecting mirror 124 also has an opening 132 for receiving one end of the high-pressure discharge lamp 1 at the center, and has a through hole 165 through which the power supply line 127 passes through a part of the side surface.

  The light source unit 110 is further held between the base 133 that holds one end of the high-pressure discharge lamp 1, the reinforcing member 134 that covers a part of the back surface of the reflecting mirror 124, and the back surface of the reflecting mirror 124 and the reinforcing member 134. And a regulating member 136. The base 133 has a cylindrical structure having an opening 135 through which one end of the lamp 123 passes and a ventilation hole 140 so that the power supply line 125 can be connected to the external lead wire 27. The ventilation hole 140 is provided for passing the wind sent from the cooling fan device that cools the internal space of the lamp 123 and the reflecting mirror 124 that becomes high temperature during operation. The ventilation hole 140 may be covered with a member (for example, a metal mesh) having a large number of holes through which air can be circulated in order to prevent dust and the like from entering the inside from the outside.

  The base 133 can be formed from an inorganic material having electrical insulation, such as steatite (MgO.SiO2). Base 133 may also be formed from any ceramic material selected from the group consisting of alumina (Al2O3), zircon cordierite (MgO-ZrSiO4), silicon carbide (SiC), and silicon nitride (Si3N4).

  The reflecting mirror 124 has a glass substrate 182 and a reflecting surface 181 formed by coating the surface of the substrate 182. The base material 182 has an outer peripheral portion having a concave shape and a cylindrical inner peripheral portion having an opening 132 for holding the lamp 123. The base material 182 of the reflecting mirror 124 has a shape close to a square when viewed from the back side. The length of one side when the reflecting mirror 124 is viewed from the back side can be, for example, about 3 cm to 10 cm. By adopting such a shape, it is possible to efficiently accommodate a light source having a large luminous flux in a limited space.

  As the shape of the reflecting surface 181, a short focus elliptical shape or a parabolic shape can be selected in a cross section including the central axis of the reflecting mirror 124. When a concave lens is used in combination with the light source unit 110, a long-focus elliptical shape can also be selected. The reflective surface 181 may be formed from a reflective layer of a dielectric multilayer film. In that case, it may be configured to selectively reflect visible light and transmit ultraviolet and infrared light. The dielectric multilayer film of the reflective surface 181 can be appropriately designed according to the wavelength of radiation (electromagnetic wave) to be used.

  The reflector 124 can be formed from, for example, crystallized glass, aluminosilicate glass, or borosilicate glass. The reflection efficiency of the reflecting mirror 124 increases as the position of the through hole 165 in the reflecting mirror 124 is closer to the front end of the reflecting surface 181. Therefore, the through hole 165 in the present embodiment is provided relatively near the front end of the reflecting surface 181.

  The configuration of the light source unit 110 is not limited to the above, and various configurations can be adopted. The configuration of the light source unit of the present disclosure is not limited to a specific one as long as the light source unit includes a high-pressure discharge lamp in which a pair of electrodes are arranged in the vertical direction.

<Drive circuit>
Next, the configuration of the drive circuit and the preferable range of lamp power in this embodiment will be described. Here, “lamp power” means the time average of the product of the voltage applied to the pair of electrodes of the high-pressure discharge lamp and the current flowing through the electrodes.

  The drive circuit in this embodiment is provided in the power supply unit 207 shown in FIG. FIG. 11 is a block diagram illustrating a configuration example of the power supply unit 207. The power supply unit 207 in this example includes a DC power supply circuit 301 that converts a commercial AC voltage into a predetermined DC voltage and outputs it, and converts a DC voltage output from the DC power supply circuit 301 into an AC voltage having a predetermined frequency. And a drive circuit 310 that supplies the unit 110. The drive circuit 310 includes a DC-DC converter 311, an inverter circuit 312, a starting operation circuit 313, and a control circuit 314.

  The DC-DC converter 311 includes, for example, a step-down chopper circuit. The DC voltage output from the DC power supply circuit 301 is stepped down to a predetermined DC voltage by the switching operation in the step-down chopper circuit. This switching operation is controlled by the control circuit 314. The control circuit 314 can be realized by a microcomputer (microcomputer), for example.

  The inverter circuit 312 is a full bridge circuit having, for example, four switching elements. The inverter circuit 312 converts the DC voltage output from the DC-DC converter 311 into an AC voltage (rectangular wave) having a predetermined frequency. This conversion is realized by the control circuit 314 switching the on / off state of each switching element.

  The starting operation circuit 313 is a resonance circuit having an inductor and a capacitor. The starting operation circuit 313 is connected to the two output terminals of the inverter circuit 312 and the two connectors 129 and 131 in the light source unit 110. The starting operation circuit 4 amplifies the AC voltage output from the inverter circuit 312 and supplies it to the high pressure discharge lamp at the time of starting. This promotes dielectric breakdown between the electrodes of the high-pressure discharge lamp.

  The drive circuit 310 in the present embodiment is configured so that the lamp power when the mercury vapor state in the arc tube changes from the saturated state to the unsaturated state is P0, and the lamp power is high so that the lamp power is in a range of 1.5P0 or less. Drive the discharge lamp. Thereby, since it can suppress that an electrode wears out by heat | fever during lighting, the lifetime of a lamp | ramp can be improved.

  In one example, the drive circuit 310 drives the high-pressure discharge lamp so that the lamp power is P0 or more and 1.5P0 or less.

  FIG. 12 is a graph showing an example of the relationship between the power and voltage of the high-pressure discharge lamp. When the lamp power falls below the threshold value P0 (about 240 W in this example), the lamp voltage starts to decrease, indicating that mercury is beginning to aggregate. That is, mercury is unsaturated when the threshold is P0 or more, and saturated when it is less than P0.

  According to the experiments by the present inventors, the effect of improving the lamp life by directing the pair of electrodes in the vertical direction is particularly high when the lamp power range is in the range of P0 to 1.5P0. I understood. When the lamp power is set to 1.6 P0 (about 380 W) and the lamp is kept on for a high-pressure discharge lamp designed to be in a vertically lit arrangement, the lamp life is that under the same conditions in the horizontally lit arrangement. 1 to 1.5 times. On the other hand, when the lamp power was set to 1.5P0 (about 360 W) and the lamp was kept on, the lamp life was improved to 1.5 to 2 times the life under the same conditions in the horizontal lighting arrangement. Furthermore, when the lamp power was set to 1.25 P0 (about 300 W) and the lamp was kept on, the lamp life was improved to more than twice the life under the same conditions in the horizontal lighting arrangement. Similarly, when the lamp power was set to another value within the range of P0 to 1.5P0, the effect of improving the life could be confirmed.

  In this way, the effect of adopting the vertical lighting arrangement is further improved by keeping the lamp power relatively low. This is due to the fact that in the vertical lighting arrangement, the time until devitrification spreads over the effective range from which light is extracted is slower as the lamp power is lower. FIG. 13A and FIG. 13B are diagrams for explaining temporal changes in the devitrification area that affects the illuminance in the horizontal lighting arrangement and the vertical lighting arrangement, respectively. These figures show the time change for each of a case where the lamp power is relatively high and a case where the lamp power is relatively low. The “devitrification area affecting illuminance” means the area of the formed devitrification part that reaches the effective range from which light is extracted. In the horizontal lighting arrangement, devitrification appears mainly in the central portion, and the devitrification affects the illuminance from the initial stage and expands as shown in FIG. 13A. On the other hand, in the vertical lighting arrangement in which devitrification appears mainly at the end, it takes time until devitrification appears and affects the illuminance, and its expansion is relatively slow. As shown in FIG. 13B. However, when the power is relatively high, devitrification portions that affect the illuminance appear relatively early, and the rate of increase is large. Therefore, the life improvement effect is higher when the lamp power is lower.

The lamp power may be set to a value within a range of 1.1P0 to 1.4P0 in one example, and may be set to a value within a range of 1.2P0 to 1.3P0 in another example. By setting the upper limit and the lower limit of the lamp power in this way, further improvement of the life can be expected. FIG. 14 shows the time variation of the illuminance maintenance rate of three samples for each of the vertical lighting arrangement and the horizontal lighting arrangement. It is a figure which shows a result. The design conditions for all three samples are the same for each of the vertical lighting arrangement and the horizontal lighting arrangement. In this experiment, a concave reflecting mirror having a size of 68 mm square when viewed from the optical axis direction was used. While performing air cooling with a DC fan, the lamp power was set to 380 W, and the lifetime was measured under the conditions of lighting for 2 hours and turning off for 15 minutes. Here, “lifetime” is defined as the time until the ratio of the illuminance at that time to the illuminance in the initial state (that is, the illuminance maintenance ratio) reaches 50%. In the example shown in FIG. 14, the life in the case of the vertical lighting arrangement is improved by about 1.3 times as compared with the life in the case of the horizontal lighting arrangement. Thus, even when the lamp power exceeds 1.5P0, the effect of improving the life due to the vertical lighting arrangement is great.

  The projector of the present disclosure can be widely used as a display device used in, for example, ordinary homes, schools, hospitals, businesses, and leisure facilities.

DESCRIPTION OF SYMBOLS 1 High pressure discharge lamp 3 Arc tube 5 Discharge space 6 Light emission part 7,9 Electrode 11,13 Sealing part 23,25 Metal foil 27,29 External lead wire 51 Trigger wire (conductor)
60, 62 Dichroic mirror 61, 64, 65 Mirror 67 First liquid crystal panel 68 Second liquid crystal panel 69 Third liquid crystal panel 71, 91 Small diameter part 72, 92 Large diameter part 73, 93 Tip 74, 94 Projection part 100 Devitrification Part 110 Light source unit 124 Concave reflector 125, 127 Feed line 129 First connector 131 Second connector 132 Open 133 Base 134 Reinforcement member 135 Open 136 Restriction member 140 Ventilation hole 181 Reflective surface 182 Reflector base material 187 Connection sleeve 189 Connection sleeve 201 Projector 207 Power supply unit 209 Optical unit 213 Case 215 Control unit 219 Projection lens 301 DC power supply circuit 310 Drive circuit 311 DC-DC converter 312 Inverter circuit 313 Start operation circuit 314 Control Control circuit 350 Effective range of light

Claims (6)

An emission tube made of quartz glass having a light emitting part in which at least mercury is enclosed and a pair of electrodes are arranged to face each other, and a pair of sealing parts extending from the light emitting part in opposite directions to each other When,
A concave reflector in which the arc tube is disposed;
An optical unit that projects an image using light emitted from the concave reflecting mirror;
With
The arc tube is arranged so that the pair of electrodes face the vertical direction,
The optical unit is a projector device configured such that a region of an image to be projected is a horizontally long rectangle.   The projector device according to claim 1, wherein the concave reflecting mirror is arranged so that an optical axis thereof is aligned with a central axis in a longitudinal direction of the pair of electrodes.   The projector device according to claim 1, wherein an angle between a longitudinal central axis of the pair of electrodes and a vertical direction is 20 ° or less. The optical unit is
At least one spatial light modulator that forms an image using light emitted from the concave reflecting mirror;
A lens for projecting an image formed by the spatial light modulator;
And having
The long side direction of the area | region of the image to project is comprised so that it may orthogonally cross with the plane parallel to both the optical axis of the said lens, and the central axis of the longitudinal direction of a pair of said electrode. The projector apparatus described in 1. A high-pressure discharge lamp having the arc tube;
A drive circuit electrically connected to the pair of electrodes and driving the high-pressure discharge lamp;
With
When the lamp power of the high-pressure discharge lamp when the state of mercury vapor in the arc tube changes from a saturated state to an unsaturated state is P0, the drive circuit has a range in which the lamp power is 1.5P0 or less. Driving the high-pressure discharge lamp with
The projector device according to claim 1.   The projector device according to claim 5, wherein the driving circuit drives the high-pressure discharge lamp in a range where the lamp power is P0 or more and 1.5P0 or less.

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