JP5077666B2 - projector - Google Patents

Description

The present invention relates to a projector.

  2. Description of the Related Art Today, a projector as an image projection apparatus that projects a screen of a personal computer, a video image, an image based on image data stored in a memory card or the like onto a screen is widely used.

  This projector incorporates a light source device composed of a small, high-brightness metal halide lamp, an ultra-high pressure mercury lamp, or the like, and the light emitted from this light source is converted into a micromirror display element called DMD through a light source side optical system, Alternatively, the light is condensed on a liquid crystal plate and a color image is displayed on the screen via the projection side optical system.

  In the projection side optical system of the projector, zoom adjustment and focus adjustment are performed by moving the optical system.

  Since the light source device built in the projector is a metal halide lamp, an ultra-high pressure mercury lamp, or the like, immediately after the projector starts up, the mercury vapor pressure enclosed in the glass tube of the lamp is low, so the luminance is low. As the time elapses, the temperature rises due to the discharge and the mercury evaporates, so that the luminance also increases. This light source device requires several minutes until mercury is completely evaporated and the brightness is stabilized.

  Further, since the light source device becomes high temperature from several hundred to nearly 1000 degrees when stabilized, the projector controls temperature by incorporating a cooling fan. At this time, heat is also transmitted to a plurality of lenses constituting the optical system due to the light source device, and the temperature of each lens is increased until the optical system reaches a thermal equilibrium state even after the luminance of the light source device is stabilized. to continue.

  As a result, each lens thermally expands and its refractive index changes, so that a phenomenon occurs in which the focal length of the optical system is shifted immediately after the luminance stabilization of the light source device and after the optical system reaches a thermal equilibrium state. become.

  Therefore, even if the user of this projector adjusts the focus by looking at the image displayed on the screen after the brightness of the light source device is stabilized, the image on the screen becomes blurred as the temperature of the optical system rises. There is a problem that it is necessary to adjust the focus again.

  Since conventional projectors do not have a function for adjusting the focus appropriately with respect to this focus change, it has been necessary to accept that the image displayed on the screen is blurred.

In addition, projectors that employ a system generally called an optical coupling system, depending on the temperature of the optical coupling liquid by skillfully utilizing the thermal expansion of the optical coupling liquid, which is one of the components of the optical system. The optical coupling lens, which is one of the projection lens systems, is shifted, and the focus change due to temperature change is automatically corrected, and at the same time, the optical coupling lens is shifted using motor power, air pressure, etc. There has been a proposal that enables arbitrary and active focus adjustment (for example, Patent Document 1).
JP-A-9-90273

  Since the proposal using the thermal expansion of the optical coupling liquid described above can only be used for projectors of the optical coupling method, projectors that do not employ this method still accept image blur due to temperature changes. Inevitably, after the start of projection, there is a problem in that focusing is performed again by focus adjustment to perform clear projection. In addition, when it is not necessary to perform fine adjustment of manual focusing immediately after the start of projection, a complicated mechanism is additionally provided in the projector, which increases the size and cost of the projector. There is a problem.

The present invention has been made in view of such problems of the prior art, it aims to provide an image blurring due to focus variation immediately after the projection start, the projector to suppress without providing a complicated mechanism It is said.

The present invention includes a plurality of lens barrels each having a lens group therein, a projection lens unit including a heating unit that preheats the plurality of lens barrels, a light source device, and an illumination side that guides light from the light source device comprising an optical unit block having a projection side block having an image generation block and projection unit comprises a block and a display device, a cooling fan, and a projector control unit, wherein the projector control unit, the display element after the lighting operation image A plurality of lens barrels having the lens group of the projection lens unit are preheated by the heating means during a standby state in which no is displayed .

According to the present invention, it is possible to provide a wear projector so possible to suppress without providing a complicated mechanism blurring of the image due to the temperature change of lenses.

  The projector 10 according to the best mode for carrying out the present invention includes a light source device 63, an optical unit block 77, a cooling fan, and projector control means. The illumination side block 78 includes a part of the illumination unit that guides the light, the image generation block 79 that includes a part of the illumination unit and the display element 51, and the projection side block 80 that includes the projection unit 130. Is.

  The projection unit 130 includes a movable lens barrel 131 having a movable lens group 97 inside, a fixed lens barrel 132 having a fixed lens group 93 inside, and a heating means 140. The fixed barrel 132 is preheated by the heating means 140.

  The heating means 140 is a film heater made of a thin sheet heating element, and is wound around and fixed to the outer edge of the movable barrel 131.

  Then, the heating means 140 generates heat when power is supplied in conjunction with the activation of the projector 10, and heats the movable barrel 131 and the fixed barrel 132 from the outside before the projector 10 displays an image on the screen. The temperature of the internal lens is raised in advance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a projector 10 according to one embodiment of the present invention has a substantially rectangular parallelepiped shape, and a lens cover 19 that covers a projection port on the side of a front plate 12 that is a side plate in front of a main body case. The front plate 12 is provided with a plurality of exhaust holes 17.

  The top plate 11 which is a main body case has a key / indicator unit 37. The key / indicator unit 37 includes a power switch key, a power indicator for notifying power on / off, a light source device, and the like. It is provided with keys and indicators such as an overheat indicator for notifying when overheated.

  Further, on the back of the main body case, various terminals 20 such as an input / output connector portion and a power adapter plug, etc., which are provided with a USB terminal, a D-SUB terminal for inputting image signals, an S terminal, an RCA terminal, etc. on the back plate, a memory not shown A card slot and an Ir receiver for receiving control signals from the remote controller are provided.

  The rear plate, the right side plate which is a side plate of the main body case (not shown), and the lower portion of the left side plate 15 which is the side plate shown in FIG. It is.

  As shown in FIG. 2, the projector control means of the projector 10 includes a control unit 38, an input / output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, and the like. The image signals of various standards input from the connector unit 21 are converted so as to be unified into an image signal of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB). Thereafter, it is sent to the display encoder 24.

  The display encoder 24 develops and stores the transmitted image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display drive unit 26.

  A display drive unit 26 to which a video signal is input from the display encoder 24 drives a display element 51, which is a spatial light modulation element (SOM), at an appropriate frame rate corresponding to the image signal sent. Yes, the light from the light source device 63 is incident on the display element 51 through the illumination unit that forms the light source side optical system, thereby forming a light image with the reflected light of the display element 51 and forming the projection side optical system. The movable lens group 97 of the projection side optical system is driven for zoom adjustment and focus adjustment by a lens motor 45. .

  In addition, the image compression / decompression unit 31 performs a recording process for sequentially writing a luminance signal and a color difference signal of an image signal to a memory card 32 that is a removable recording medium by performing data compression by processing such as ADTC and Huffman coding. In the mode, the image data recorded on the memory card 32 is read, and individual image data constituting a series of moving images is expanded in units of one frame and sent to the display encoder 24 via the image conversion unit 23. A moving image or the like can be displayed based on the stored image data.

  The control unit 38 controls the operation of each circuit in the projector 10, and includes a ROM that stores operation programs such as a CPU and various settings fixedly, and a RAM that is used as a work memory. ing.

  Further, the operation signal of the key / indicator unit 37 composed of the main key and the indicator provided on the upper surface plate 11 of the main body case is directly sent to the control unit 38, and the key operation signal from the remote controller is received by Ir. The code signal received by the unit 35 and demodulated by the Ir processing unit 36 is sent to the control unit 38.

  An audio processing unit 47 is connected to the control unit 38 via a system bus (SB). The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and converts the audio data into analog data in the projection mode and the playback mode. The speaker 48 can be driven to emit loud sounds.

  The control unit 38 controls a power supply control circuit 41. The power supply control circuit 41 turns on the discharge lamp of the light source device 63 when the power switch key is operated. Further, the control unit 38 also controls a cooling fan drive control circuit 43. The cooling fan drive control circuit 43 performs temperature detection by a plurality of temperature sensors provided in the light source device 63, etc. The rotation speed is controlled, and the rotation of the cooling fan is continued even after the lamp of the light source device 63 is turned off by a timer or the like. Further, depending on the result of temperature detection by the temperature sensor, the light source device 63 is stopped and the projector body It also performs control such as turning off the power of the.

  As shown in FIG. 3, the projector 10 has an internal structure in which a power supply control circuit board 102 with a lamp power supply circuit block 101 and the like mounted thereon is disposed in the vicinity of the right side plate 14 and the inside of the casing is divided by a partition wall 120. The intake side space chamber 121 on the back plate 13 side and the exhaust side space chamber 122 on the front plate 12 side are formed in an airtight manner, and a sirocco fan type blower 110 is arranged as a cooling fan near the center of the projector 10, and the intake side space The suction port 111 of the blower 110 is positioned in the chamber 121 and the discharge port 113 of the blower 110 is positioned in the exhaust side space chamber 122.

  Further, a light source device 63 is disposed in the exhaust side space 122, and an optical unit block 77 including an illumination side block 78, an image generation block 79, and a projection side block 80 is disposed along the left side plate 15. 77. The illumination side block 78 is communicated with the exhaust side space chamber 122 so that a part of the illumination unit provided in the illumination side block 78 is located in the exhaust side space chamber 122. An exhaust temperature reducing device 114 is disposed along the face plate 12.

  The light source device 63 has a reflector having a reflection film on the inner surface and having an opening in the front, and a discharge lamp using halogen or the like built in the reflector.

  The blower 110 as a cooling fan for cooling the light source device 63 and the like has a suction port 111 at the center, and the discharge port 113 has a substantially square cross section, and is connected to the partition partition 120, and the partition partition Exhaust air from the blower 110 is discharged into the exhaust-side space chamber 122 partitioned by 120, and a control circuit board 103 is disposed in the vicinity of the suction port 111 of the blower 110.

  The optical unit block 77 is disposed in the vicinity of the light source device 63, and includes an illumination side block 78 that includes a part of the illumination unit and emits light emitted from the light source device 63 toward the image generation block 79, and illumination. An image generation block 79 that includes a part of the display unit 51 and the display element 51 and reflects the emitted light from the illumination side block 78 to the projection side block 80 in accordance with the image data, and a projection unit of the left side plate 15 It is composed of three blocks, a projection side block 80 which is arranged in the vicinity and projects the light reflected by the image generation block 79.

  A part of the illumination unit forming the light source side optical system 61 provided in the illumination side block 78 is a first reflection mirror 72 that reflects the light emitted from the light source device 63 to the color wheel 71 as shown in FIG. In addition, a color filter for red light, green light, and blue light is provided around the color wheel 71 that is rotated by the wheel motor 73, and light that has passed through the filter of the color wheel 71 is converted into a light beam having a uniform intensity distribution. Optical device 75 and the like.

  In addition, a part of the illumination unit forming the light source side optical system 61 included in the image generation block 79 includes a second reflection mirror 74 that changes the direction of light emitted from the light guide device 75, and the second reflection mirror. A condensing lens group 83 for condensing the light reflected by 74 on the display element 51 and an irradiation mirror 84 for irradiating the light transmitted through the condensing lens group 83 to the display element 51 at a predetermined angle. The image generation block 79 includes a DMD (digital micromirror device). A display element heat dissipation plate 53 for cooling the display element 51 is disposed on the back plate 13 side of the display element 51.

  In this DMD, a plurality of micromirrors are arranged in a matrix, and light incident from an incident direction inclined in one direction with respect to the front direction is converted into an on-state light beam in the front direction by switching the tilt direction of the plurality of micromirrors. The image is displayed by being reflected separately from the off-state light beam in the oblique direction, and the light incident on the micromirror tilted in one tilt direction is reflected in the front direction by this micromirror and turned on. The light incident on the micromirror tilted in the other tilt direction is reflected by the micromirror in an oblique direction to form an off-state light beam, and the off-state light beam is absorbed by the light absorption plate and reflected in the front direction. The image is generated by the bright display by and the dark display by reflection in the oblique direction.

  The projection-side block 80 includes a projection unit that forms a projection-side optical system 62 that irradiates a screen or the like (not shown) with a light beam having a bright display for forming an image. A movable lens group 97 is provided. The lens group of these projection-side optical systems 62 is a variable-focus lens having a zoom function, and is described above by the optical system control board 86 disposed between the optical unit block 77 and the left side plate 15. The lens motor 45 is controlled to move the movable lens group 97 along the optical axis, thereby enabling zoom adjustment and focus adjustment.

  Further, in order to move the movable lens group 97 along the optical axis in this way, the projection unit 130 of the projection side block 80 is provided with a lens barrel fixing plate 133 on the front as shown in FIG. A holding member 135 is disposed in the vicinity of the back surface of the fixed plate 133, the fixed lens barrel 132 is fixed to the lens barrel fixing plate 133 and the holding member 135, and two sliding support shafts 134 are lighted in the vicinity of both ends of the holding member 135. The lens motor 45 is disposed in the vicinity of the lower end of the holding member 135, and the coupling shaft 138 is coupled to the lens motor 45 and disposed in parallel with the sliding support shaft 134. Two movable lens barrels 131 are pivotally supported on the shaft 134 and are connected to the connecting shaft 138 at the bottom, and a holding plate 136 for fixing the fixed lens barrel 132 is disposed at the rear to hold the sliding support shaft 134. It is what.

  Each of the two movable lens barrels 131 includes a cylindrical lens barrel portion 141 in which the movable lens group 97 is housed, and a sliding support shaft formed so as to protrude in a radial position of the lens barrel portion 141. The first arm 142 and the second arm 143 are connected to the bearing 134 and supported by the sliding support shaft 134 so as to be slidable along the sliding support shaft 134.

  Each of the first arms 142 includes a first connecting portion 144 that is slidably supported on the sliding support shaft 134, and a movable support portion 145 that is connected to the connecting shaft 138. 144 is a substantially rectangular parallelepiped shape having an opening on one side, the longitudinal direction is parallel to the sliding support shaft 134, and the surface perpendicular to the sliding support shaft 134 is substantially the same as the outer diameter of the sliding support shaft 134. A through hole is formed and slides along the sliding support shaft 134. Each movable support portion 145 includes a through hole that is positioned below the first connecting portion 144 and has a female screw that is threadedly engaged with a connecting shaft 138 that has a male screw formed on the outer periphery thereof. Each movable lens barrel 131 is moved in the optical axis direction by the rotation of each connecting shaft 138 connected to each rotating shaft of the lens motor 45 that passes therethrough. Further, the second arm 143 provided on the opposite side of the first arm 142 is provided with a U-shaped second connecting portion 146 at the tip, and the second connecting portion 146 can slide on the sliding support shaft 134. It is supported by the shaft.

  As shown in FIG. 6, the outer periphery of the two movable lens barrels 131 storing the movable lens group 97 and the fixed lens barrel 132 storing the fixed lens group 93, which are respectively arranged before and after the movable lens barrel 131. A heating means 140, which is a film heater made of a thin sheet heating element, is wound and fixed with an adhesive having excellent heat resistance. In addition, it is preferable that the winding range covers substantially the entire circumference of the outer edge.

  The film heater as the heating means 140 is formed by laminating a heater circuit as a heating resistor made of nickel alloy, stainless steel or the like with an insulating material such as polyimide or polyethylene terephthalate having excellent heat resistance. . Such a film heater has a thickness of several tens to hundreds of μm, and the lead wire 151 connecting the film heater and the power source has a small diameter, so that the space of the projector 10 can be freely expanded. In addition, the inside of the projector 10 can be routed. In this example, a lead extraction portion 152 that is a connection portion between the heater circuit and the lead wire 151 is provided in the first arm 142 in the vicinity of the movable barrel 131 in the movable barrel 131, and in the fixed barrel 132, The lead wire 151 is provided on the outer edge of the fixed barrel 132 and connected to an internal power source of the projector 10 (not shown).

  When the power switch key is operated, the projector 10 turns on the discharge lamp of the light source device 63 shown in FIG. 3 and drives the cooling fan, so that the left side plate 15, the right side plate 14, and the rear plate 13 The outside air is taken in from the intake hole 18, the air inside is exhausted from the exhaust hole 17 of the front plate 12, and the heating means 140 shown in FIG. In addition, heat is applied to the lens groups 93 and 97 housed inside from the outside of the fixed barrel 132 via the barrels 131 and 132, and the projector 10 is set in a standby state while the temperature is increased. This standby state is maintained until the brightness of the light source is stabilized, and in the standby state, the DMD is controlled so as not to display an image on the screen.

  The projector 10 continues to rise in temperature until all of the elements constituting the projector 10 are in a substantially thermal equilibrium state even after the standby state ends with the stabilization of luminance and an image is displayed on the screen. That is, in the past, there was a large gap in the time from the end of the standby state until the temperature of the lens group of the projection-side optical system 62 is stabilized and the steady state is reached. Even if the focus adjustment was performed by looking at the image, the temperature of the lens group continued to rise, and the image was blurred, and the focus adjustment was necessary again.

  However, the heating means 140 in this embodiment generates heat when the projector 10 is started, and the lens is preheated using the standby state time. The time interval until the temperature of the lens group is stabilized can be reduced.

  And as a preheating control method using the heating means 140, a temperature sensor may be provided around the lens barrels 131 and 132, the temperature may be detected, and the power ON / OFF of the heating means 140 may be controlled, A timer may be used.

  The heating means 140 may be wound and fixed only on the movable lens barrel 131, or conversely, may be wound and fixed only on the fixed lens barrel 132. In this case, there will be a difference in the time until the temperature of the lens groups installed in each lens barrel stabilizes, but the image defocusing caused by the time difference is fine enough to be acceptable. It is. However, if the heating means 140 is provided on both the movable lens barrel 131 and the fixed lens barrel 132 and is wound over substantially the entire circumference of the outer edge of the movable lens barrel 131 and the fixed lens barrel 132, the outer peripheral edge of the lens installed inside the lens barrel 131, 132 is substantially uniform Heat is applied, and the lens group can be efficiently preheated.

  In this manner, the temperature of the projector 10 is stabilized from the end of the standby state by winding and fixing the heating means 140 around the lens barrels 131 and 132, causing the heating means 140 to generate heat when the projector 10 is started, and preheating the lens. Can be reduced. As a result, after the user finishes standby, the user sees the image displayed on the screen and adjusts the focus once, so that the subsequent image does not cause blurring of the image due to defocusing enough to be recognized by humans. There is no need to perform focus adjustment again. Further, the heating means 140 can omit a complicated mechanism for adjusting the focus with respect to the temperature change of the lens group forming the projection-side optical system 62, and can also reduce the cost of parts and manufacturing. is there.

  Then, as shown in FIG. 7, the heating means 140 may be a heating element that can be bent and wound in a thin line shape. The heating means 140 is formed by enclosing a heating wire and an insulator such as magnesium oxide inside a tube made of stainless steel or the like. Since the heating means 140 has an outer diameter of several mm, it can be easily attached even in a narrow place. Therefore, the movable lens 131 and the fixed lens tube 132 can be easily wound and fixed, and the same effects as described above can be obtained. In this example, the hole 153 through which the heating means 140 is inserted is formed in the vicinity of the outer edge of the first arm 142 connected to the movable lens tube 131, thereby facilitating winding and fixing. It is.

  Further, as shown in FIG. 8, the heating means 140 may be a micro ceramic heater formed of an alumina substrate excellent in heat resistance and insulation and a platinum-based resistor excellent in heat resistance and insulated by an alumina sheet. . The heating means 140 is, for example, a rectangular sheet having a length and width of several tens of millimeters and a thickness of several millimeters, and is provided with a lead extraction portion 152 at one end, so that it can be easily attached even in a narrow place. It is something that can be done. Therefore, by adhering the plurality of heating means 140 to the outer edges of the movable lens barrel 131 and the fixed lens barrel 132 with an adhesive or the like so that the respective installation intervals are substantially equal, the same effects as described above can be obtained. is there.

  The present invention is not limited to the above-described embodiments, and can be freely changed and improved without departing from the gist of the invention.

1 is a perspective view showing an external appearance of a projector according to an embodiment of the invention. FIG. 3 is a diagram illustrating a functional circuit block of the projector according to the embodiment of the invention. FIG. 3 is a top view of the projector according to the embodiment of the present invention with the top plate removed. FIG. 3 is a top view showing the inside of the optical unit block of the projector according to the embodiment of the invention. The perspective view of the projection unit which concerns on the Example of this invention. The figure which shows the state which wound and fixed to the outer periphery of the lens-barrel as a heating means which concerns on the Example of this invention as a film heater. The figure which shows a projection unit when the heating means which concerns on the Example of this invention is used as the thin linear heating element. The figure which shows a projection unit when the heating means which concerns on the Example of this invention is used as the micro ceramic heater.

Explanation of symbols

10 Projector 11 Top plate
12 Front plate 13 Back plate
14 Right side plate 15 Left side plate
17 Exhaust hole 18 Intake hole
19 Lens cover 20 Various terminals
21 I / O connector 22 I / O interface
23 Image converter 24 Display encoder
25 Video RAM 26 Display driver
31 Image compression / decompression unit 32 Memory card
35 Ir receiver 36 Ir processor
37 Key / Indicator section 38 Control section
41 Power supply control circuit 43 Cooling fan drive control circuit
45 Lens motor 47 Audio processor
48 Speaker 51 Display element
53 Display element heat sink 61 Light source side optical system
62 Projection-side optical system 63 Light source device
71 Color wheel 72 First reflection mirror
73 Wheel motor 74 Second reflection mirror
75 Light guide device 77 Optical unit block
78 Lighting block 79 Image generation block
80 Projection side block 83 Condensing lens group
84 Irradiation mirror 86 Optical system control board
93 Fixed lens group 97 Movable lens group
101 Lamp power circuit block 102 Power control circuit board
103 Control circuit board 110 Blower
111 Suction port 113 Discharge port
114 Exhaust temperature reduction device 120 Partition wall
121 Inlet side space 122 Exhaust side space
130 Projection unit 131 Movable lens barrel
132 Fixed lens tube 133 Fixed tube tube
134 Sliding support shaft 135 Holding member
136 Holding plate 138 Connecting shaft
140 Heating means 141 Lens barrel
142 First arm 143 Second arm
144 First connection part 145 Movable support part
146 Second connecting part 151 Lead wire
152 Lead outlet 153 hole

Claims (6)

A projection lens unit including a plurality of lens barrels each including a lens group and heating means for preheating the plurality of lens barrels;
A light source device;
An optical unit block having an illumination side block for guiding light from the light source device, an image generation block including a display element, and a projection side block including a projection unit;
A cooling fan,
Projector control means;
Equipped with a,
The projector control means preheats a plurality of lens barrels provided with the lens group of the projection lens unit by the heating means during a standby state in which the display element after the lighting operation does not display an image. Projector. Further, according to claim 1, characterized in that preheating the temperature sensor is provided in the periphery of the lens barrel, a plurality of barrel with the lens group of the projection lens unit in the interior to a predetermined temperature by the heating means projector. The projector according to claim 1 , wherein the heating unit is wound and fixed around an outer edge of the barrel. 4. The projector according to claim 1 , wherein the heating means is a film heater made of a thin sheet heating element. The projector according to any one of claims 1 to 3 , wherein the heating means is formed of a heating element that is a thin wire and can be bent and wound. The projector according to claim 1 , wherein the heating unit is a micro ceramic heater.

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