JP5246467B2 - Distance measuring device and projector - Google Patents

Description

  The present invention relates to a distance measuring device suitable for a projector and a projector equipped with the distance measuring device.

  2. Description of the Related Art Today, data projectors that project an image displayed on a personal computer screen, an image of a video signal, an image based on image data stored in a memory card or the like onto a screen are widely used.

  In many cases, data projectors use small high-intensity light sources such as metal halide lamps and ultra-high pressure mercury lamps, and light emitted from the light sources is converted into light of three primary colors by a color filter. A display element called a “micromirror device” is irradiated, and the transmitted light or reflected light of the display element is projected onto a screen through a lens group that is a projection-side optical system having a zoom function.

  In such a projector, in order to correct (keystone correction) trapezoidal distortion that occurs in the projected image according to the tilt angle and projection angle of the screen surface, as well as focus adjustment that projects the image clearly according to the distance from the screen surface. Therefore, it is necessary to accurately measure the distance to the screen surface, the inclination angle of the screen surface, and the projection angle. For this reason, there are many proposals regarding a projector having a distance measuring device that measures the distance from the projector to a plurality of locations on the screen. Has been made.

  One of the common distance measuring apparatuses is an optical distance measuring apparatus using a laser beam. This optical distance measuring device irradiates a target with a laser beam and receives reflected light from the target with a light receiving element such as an avalanche photodiode (APD) to perform distance measurement.

  In a projector equipped with this optical distance measuring device, in order to accurately measure the distance to the screen, the tilt angle of the screen, and the projection angle, the distance to at least three points that are not aligned on a straight line on the screen surface Need to be measured. Further, in order to prevent the laser projection point from deviating from the screen surface, the three points for measuring the distance need to be located within the screen surface. Furthermore, in order to obtain an accurate inclination of the projected image, the distance between the three points needs to be as far as possible.

  However, many current projectors have a zoom function, and the projected image when projected onto a small screen and the projected image when projected onto a large screen with the same distance to the screen are small. When three points satisfying the above-mentioned conditions are determined on the screen, the three points on the large screen are in a small range on the screen, and the above-mentioned conditions cannot be satisfied. On the other hand, when three points satisfying the above-mentioned conditions are determined on a large screen, the three points are located outside the small screen, and the distance and inclination from the small screen surface cannot be measured. It will be. For this reason, the accuracy of the keystone correction using the distance measuring device varies depending on the size of the screen and the distance from the screen, and it has been difficult to provide a projector that can project clear images in various situations.

In order to solve such problems, Japanese Patent Application Laid-Open No. 2005-249432 (Patent Document 1) discloses a line sensor that uses reflected light of an image pattern of a predetermined size projected on a screen as light receiving elements in the vertical direction and the horizontal direction. The sensor unit obtains sensor data from the output of the line sensor, calculates the number of extreme values that the sensor data takes extreme values in the control unit, and compares the number of extreme values obtained in the control unit with the reference number of extreme values. By adjusting the size of the image pattern to a size that can obtain the reference number of extreme values, and setting the size of the image pattern that can obtain the number of reference extreme values to a size that can obtain the desired distance measurement accuracy. There has been proposed a projector equipped with a distance measuring device that can obtain accurate distance data.
JP 2005-249432 A

  In general, in a projector having a zoom function, it has been difficult to perform appropriate keystone correction according to changes in the size of the screen and the distance to the screen depending on the conventional distance measuring device. In addition, a projector capable of keystone correction in accordance with the zoom change needs to include a plurality of light receiving elements of the distance measuring device, which causes a problem that the manufacturing process becomes complicated and the production cost increases.

  The present invention has been made in view of such problems of the prior art, and by changing the direction of laser light irradiation, distance measurement with a screen under various projection conditions is possible according to the size of the screen. An object of the present invention is to provide a projector equipped with a simple distance measuring device.

The distance measuring device of the present invention is arranged at equal intervals on a frustoconical light receiving barrel having a wide opening side on the front side and a narrow opening side on the rear side and an outer surface of the light receiving barrel, and irradiates a laser beam forward. and three of the laser unit, and one of the light receiving element for receiving reflected light from the center to the distance measurement target narrow opening side of the rear of the light-receiving barrel of three of the laser beam emitted from the laser unit an optical element for changing the direction of widening or narrowing the interval irradiation direction each other, but with a.

  According to the present invention, a distance measuring device capable of measuring the distance to the screen under various projection conditions according to the size of the screen by changing the irradiation direction of the laser light, and a projector including the distance measuring device are provided. Can be provided.

  The projector 1 in the best mode for carrying out the present invention includes a light source device 80, a light source side optical system, a display element 50, a projection side optical system having a zoom mechanism 90, projector control means, and a distance measuring device. 15 and an inclination angle calculation unit 46 as an inclination angle calculation unit and a distance calculation unit 45 as a distance calculation unit, and the distance measurement device 15 includes a distance measurement unit 51 and a measurement position adjustment unit 52. .

  The distance measuring device 15 includes a plurality of laser units 58 that irradiate laser beams, and a light receiving element 56 that is disposed at the center of the plurality of laser units 58 that receive reflected light from a distance measurement target. An optical element that changes the irradiation direction of each laser beam irradiated from 58 in a direction that widens or narrows the distance from each other is provided.

  The optical element is a concave lens 61 whose distance from the laser unit 58 is variable. The operation of the concave lens 61 is controlled by a measurement position adjusting unit 52 that is linked to the movement of the movable lens 91 of the projection side optical system. Is.

  The measuring position adjusting unit 52 includes a ranging lens barrel 62 having a concave lens 61 fixed and slidable in the front-rear direction and having a ranging cam pin 62a on the outer wall, and a ranging lens barrel 62. A distance measuring main barrel 63 that is slidably held, and a distance measuring ring 64 that has a cam groove on the inner wall located on the outer peripheral edge of the distance measuring main barrel 63 and on which the distance measuring cam pin 62a slides. A distance measuring lens barrel 62 to which the concave lens 61 is fixed as the distance measuring ring 64 rotates, and slides in the front-rear direction, and is a screen of light emitted from the laser unit 58 of the distance measuring unit 51. The irradiation position on the 85th surface is changed.

  The concave lens 61 of the measurement position adjusting unit 52 is connected by the zoom mechanism 90 of the projection side optical system and the gear box 65, and operates in conjunction with the movement of the movable lens 91.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the projector 1 according to the embodiment of the present invention includes a projection port 14 and a distance measuring device 15 in the vicinity of the side of the front plate 12 of the main body case, and from the vicinity of the distance measuring device 15 to the vicinity of the other end. A plurality of exhaust holes 16 are formed through which exhaust air that has cooled the inside of the projector 1 is exhausted, and an Ir receiver that receives a control signal from a remote controller is provided (not shown).

  The top plate 11 which is a main body case is provided with a key / indicator unit 37 and an audio output unit 18. The key / indicator unit 37 includes a power switch key, a power indicator for notifying power on / off, and a light source. It is provided with keys and indicators such as a lamp switch key for turning on the lamp of the device, a lamp indicator for displaying the lighting of the lamp, and an overheat indicator for notifying when the light source device is overheated.

  Further, although not shown on the back surface of the main body case, various terminals 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 image signal input, an S terminal, an RCA terminal, etc. It has a memory card slot and the like.

  Also, the right side plate 13 that is the side plate of the main body case and the left side plate that is the side plate (not shown) each have a plurality of air intake holes 19, and the bottom plate that is the bottom surface of the main body case has an expansion function that adjusts the projection angle. The forefoot 20 having the above is projected, and an image is projected onto the screen while being tilted upward.

  The projector 1 has a power supply control circuit board having a lamp power supply circuit block and the like, and a main circuit block having a projector control means, and a cooling fan for reducing the internal temperature of the projector 1 A high-intensity light source device including a halogen lamp as a light source means, a DMD (digital micromirror device) as a display element for generating an image, and condensing light from the light source device on the display element A light source side optical system, a projection side optical system that projects light emitted from the DMD onto a screen, and a distance measuring device that measures a distance from the screen are provided.

  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 turned into the on-state light beam reflected in the front direction by this micromirror. The light incident on the micro mirror tilted in the other tilt direction is reflected by the micro mirror in an oblique direction to form an off-state light beam, and the off-state light beam is absorbed by the light-absorbing plate and reflected in the front direction. An image is generated by bright display and dark display by reflection in an oblique direction.

  As shown in FIG. 2, the projector control means of the projector 1 includes a control unit 38, an input / output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, etc. The image signals of various standards input from 21 are converted so as to be unified into image signals of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB). 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 driving unit 26 to which a video signal is input from the display encoder 24 drives a display element 50 that is a spatial light modulation element (SOM) at an appropriate frame rate in response to an image signal sent thereto. The light from the light source device 80 is incident on the display element 50 through the light source side optical system, thereby forming an optical image with the reflected light of the display element 50 and projecting the image on a screen (not shown) through the projection side optical system. The movable lens group 89 of the projection-side optical system is driven in the optical axis direction by the lens motor 42, and zoom magnification adjustment and focus adjustment are thereby performed.

  The image compression / decompression unit 31 performs a recording process for sequentially writing the luminance signal and color difference signal of the image signal into a memory card 32 which is a removable recording medium by compressing the data by processing such as ADTC and Huffman coding, Reads out the image data recorded in the memory card 32, decompresses each image data constituting a series of moving images in units of one frame, sends them to the display encoder 24 via the image conversion unit 23, and stores them in the memory card 32. It is possible to display a moving image or the like based on the image data.

  The distance calculation unit 45 measures the distance between a plurality of points on the screen based on an electrical signal converted by the distance measurement device 15 and a light receiving element included in the distance measurement device 15 described later, and calculates an average distance from the screen. The tilt angle calculation unit 46 calculates the tilt angle of the screen from the distances to a plurality of points on the screen calculated by the distance calculation unit 45. Then, the distance calculation unit 45 and the inclination angle calculation unit 46 transmit the calculated distance to the screen and the data of the inclination angle of the screen to the distortion correction unit 47, and the average distance from the screen calculated by the distance calculation unit 45 is the lens This is used in focus adjustment by the motor 42.

  The distortion correction unit 47 performs distortion correction of the projected image based on the data received from the distance calculation unit 45 and the inclination angle calculation unit 46 and the position information of the movable lens from the position search sensor described later, and passes through the image conversion unit 23. Then, the image signal after distortion correction is transmitted to the display encoder 24, and the projection image after distortion correction can be displayed.

  The control unit 38 controls the operation of each circuit in the projector 1, and includes a ROM that stores operation programs such as a CPU and various settings in a fixed manner, a RAM that is used as a work memory, and the like. .

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

  An audio processing unit 48 is connected to the control unit 38 via a system bus (SB). The audio processing unit 48 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 reproduction mode. The speaker 49 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 when the lamp 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 or the like, thereby rotating the cooling fan. The speed is controlled, and the rotation of the cooling fan is maintained even after the lamp of the light source device 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 is stopped to Control such as turning it off is also performed.

  Next, a distance measuring device 15 that measures the distance to the screen using a laser beam arranged on the front plate 12 of the projector 1 in this embodiment will be described. A general laser rangefinder emits a laser beam by blinking at a predetermined frequency, and calculates a distance from a phase difference between transmission and reception. However, in order to perform distortion correction in the projector 1, it is necessary to calculate the tilt angle of the screen. In order to calculate the tilt angle of the screen, three points on the screen that are not on a straight line and the projector 1 It is necessary to measure the distance.

  Therefore, the distance measuring device 15 is arranged at a position near the projection side optical system so that the central axis of the distance measuring device 15 is parallel to the optical axis of the projection side optical system, as shown in FIGS. The distance measurement unit 51 and the measurement position adjustment unit 52 are formed of a distance measurement substrate 55, a light receiving element 56 disposed on the distance measurement substrate 55, and open at both end surfaces. And a light-receiving barrel 57 arranged so as to cover the periphery of the light-receiving element 56, and laser beams arranged radially in three directions of the outer surface of the light-receiving barrel 57 are emitted. It comprises three laser units 58, a light receiving lens 59 disposed at the tip of the light receiving barrel 57, and a concave lens 61 that is an optical element disposed on the optical axis of the three laser units 58. is there.

  The measurement position adjusting unit 52 includes a slidable distance measuring lens barrel 62 that fixes the concave lens 61, and a distance measuring main lens barrel 63 in which the distance measuring lens barrel 62 is slidably held. A distance measuring ring 64 that controls sliding of the distance measuring lens barrel 62, and this measurement position adjusting unit 52 is connected to the projection side optical system by a gear box 65, and a movable lens 91 to be described later. The concave lens 61 is operated back and forth in conjunction with the above operation.

  The distance measuring board 55 of the distance measuring unit 51 includes a laser unit control unit that controls the laser unit 58 in a time-sharing manner, and the light data received by the light receiving element 56 is used as the calculating unit of the distance calculating unit 45 described above. The light receiving element 56 is fixed.

  The light receiving element 56 of the distance measuring unit 51 is a highly sensitive light receiving element that amplifies an optical signal by utilizing an avalanche multiplication phenomenon caused by an avalanche phenomenon such as an avalanche photodiode (APD). Used as a light receiving element in the meter, receives the laser beam emitted from the laser unit 58 and reflected on the screen and converts it into an electric signal, and this electric signal is transmitted through the distance measuring board 55 to the above-mentioned distance. This is transmitted to the calculation means of the calculation unit 45.

  In addition, the light receiving column 57 of the distance measuring unit 51 is a truncated cone having a front and rear opening, and prevents unwanted external light from entering the light receiving element 56. A light receiving element 56 is disposed at the center on the opening side, a light receiving lens 59 is disposed so as to block the front end portion on the wide opening side, and is disposed perpendicular to the distance measurement substrate 55.

  The laser unit 58 of the distance measuring unit 51 includes a laser light source that emits a laser beam that is linear light, and is light-time-controlled by the laser unit control unit of the distance measuring substrate 55, One is arranged above the light-receiving barrel 57 and two below are arranged radially with an equal inner angle. As described above, the light is arranged radially on the outer surface of the light-receiving barrel 57 with an equal inner angle, so that light can be emitted toward different vertices of arbitrary triangles on the screen.

  Further, the light receiving lens 59 of the distance measuring unit 51 is disposed so as to close the end portion on the wide opening side of the light receiving barrel 57, and is a lens that condenses light on the light receiving element 56, and includes three laser units 58. The three fan-shaped condensing lenses corresponding to each laser unit 58 in FIG. 5 are arranged adjacent to each other in the circumferential direction, and receive light emitted from the laser unit 58 and reflected on the screen and incident on the light receiving column 57. The light is refracted toward the element 56.

  The concave lens 61, which is an optical element of the distance measuring unit 51, is fixed to the distance measuring lens barrel 62 and is movable in the front-rear direction together with the measurement lens barrel 62, and the distance from the laser unit 58 is variable. The laser beam emitted from each laser unit 58 is arranged on the optical axis of the laser unit 58 so as to pass through the concave lens 61. The concave lens 61 changes the distance between the three laser beams by increasing or decreasing the distance from the laser unit 58, and the laser beam emitted from the laser unit 58 is projected on the screen. It adjusts so that it may irradiate a wide range. In other words, the concave lens 61 is changed so as to reduce the degree of widening the distance between the laser beams when approaching the laser unit 58, and is changed so as to greatly increase the distance between the laser beams when moved away from the laser unit 58. By changing the distance between the laser beams so as to increase or decrease at the same time, it is possible to adjust the extent to which the laser beams are mutually expanded according to the distance from the laser unit 58.

  The distance measuring lens barrel 62 of the measurement position adjusting unit 52 includes a step where the rear end of the concave lens 61 is engaged with the inner wall, and a cam groove of a distance measuring ring 64 described later at a predetermined position on the outer peripheral edge. A distance measuring cam pin 62a that slides along the distance, and this distance measuring cam pin 62a is inserted into a through hole of a distance measuring main barrel 63, which will be described later, and engages with a cam groove of the distance measuring ring 64 It is what you are doing.

  The distance measuring main barrel 63 of the measurement position adjusting unit 52 holds the distance measuring lens barrel 62 so as to be slidable, and the distance measuring cam pin 62a is inserted into a predetermined position. It has a hole. The through hole has a width in the circumferential direction substantially equal to the width of the distance measuring cam pin 62a, and is formed slightly longer than the moving length of the distance measuring lens barrel 62 in the front-rear direction.

  Further, the distance measuring ring 64 of the measuring position adjusting unit 52 is rotatably arranged on the outer wall peripheral edge of the distance measuring main barrel 63, and a cam groove for engaging the distance measuring cam pin 62a is formed on the inner wall. Has been. The cam groove is formed so as to obliquely cross the inner wall from a position near the rear end of the distance measuring ring 64 to a position near the front end. Further, teeth that mesh with a distance measuring gear 67 of a gear box 65 described later are formed on the outer wall of the distance measuring ring 64.

  Then, when the distance measuring ring 64 rotates the periphery of the distance measuring main barrel 63, the distance measuring cam pin 62a locked to the cam groove is supported by the cam groove so that the distance measuring main barrel 63 is inserted. The distance lens barrel 62 is also moved in the front-rear direction by sliding the hole in the front-rear direction and supported by the distance-measuring cam pin 62a, so that the concave lens 61 is operated in the front-rear direction. As a result, the distance between the laser unit 58 and the concave lens 61 changes, so that the laser beam is refracted by the lens 61 and the irradiation position on the screen changes.

  The projection-side optical system includes a fixed lens group and a movable lens group, and is held by the projection-side main lens barrel 93. When the movable lens group operates in the optical axis direction, focus adjustment and zooming of the projected image are performed. Adjustment is possible. This movable lens group includes a focus adjustment unit and a zoom adjustment unit. The zoom adjustment unit moves the movable lens unit to adjust the zoom magnification of the projected image, and the focus adjustment unit moves a part of the movable lens group. This adjusts the focus of the image.

  The zoom mechanism 90 of the zoom adjustment unit includes a movable lens 91 disposed in the vicinity of the front end of the projection-side main barrel 93, a movable lens barrel 92 slidable in the optical axis direction for fixing the movable lens 91, and a projection. A side main barrel 93 and a projection side ring 94 capable of rotating the periphery of the projection side main barrel 93 are provided, and a position search sensor 86 is disposed in the vicinity of the projection side ring 94.

  In addition, the movable lens barrel 92 has a step where the rear end of the movable lens 91 is engaged with the inner wall, and the projection side cam pin slides along a cam groove of the projection side ring 94 described later at a predetermined position on the outer peripheral edge. The projection-side cam pin 92a is inserted through a through-hole of the projection-side main barrel 93, which will be described later, and is engaged with the cam groove of the projection-side ring 94.

  Further, the projection-side main barrel 93 holds the projection-side optical system, holds the movable lens barrel 92 so as to be slidable, and allows the projection-side cam pin 92a to penetrate at a predetermined position. It has a hole. The through hole has a circumferential width that is slightly larger than the width of the projection-side cam pin 92a, and a longitudinal length that is smaller than the longitudinal length of the projection-side ring 94.

  The projection-side ring 94 is rotatably disposed on the outer wall periphery of the projection-side main barrel 93, and a cam groove that engages the projection-side cam pin 92a is formed on the inner wall. Further, teeth that mesh with a projection-side gear 66 of a gear box 65 described later are formed on the outer wall of the projection-side ring 94. The cam groove is formed so as to obliquely cross the inner wall from a position near the rear end of the projection side ring 94 to a position near the front end.

  The position search sensor 86 is arranged in the vicinity of the movable lens 91, grasps the current position of the movable lens 91, and transmits this position information to the projector control means. The zoom magnification is calculated from the position information, and the distortion correction unit 47 is made to perform keystone correction based on the information calculated by the distance calculation unit 45 and the inclination angle calculation unit 46 described above and the zoom magnification.

  Then, similarly to the measurement position adjusting unit 52 described above, when the projection-side ring 94 rotates the peripheral edge of the projection-side main barrel 93, the zoom mechanism 90 causes the projection-side cam pin 92a locked to the cam groove to become the cam groove. Since the movable lens barrel 92 is also supported by the projection-side cam pin 92a and is moved in the front-rear direction, the movable lens 91 is moved in the front-rear direction. Operates and changes the magnification of the projected image.

  The gear box 65 includes a projection side gear 66, a distance measuring gear 67, and a connecting gear (not shown). Then, the projection-side gear 66 meshes with the teeth and connection gear formed on the outer wall of the projection-side ring 94, and the distance measurement gear 67 meshes with the teeth and connection gear formed on the outer wall of the distance measurement ring 64. It is what. Thus, when the projection side ring 94 is rotated, the distance measuring ring 64 is similarly rotated. When the zoom function is used when projecting an image on the projector 1, the laser unit 58 emits light in accordance with the magnification variation of the projected image. The irradiation position of the laser beam on the screen surface fluctuates.

  Then, as shown in FIG. 5, the projector 1 of the present invention emits laser beams from the laser unit 58 to three points in the vicinity of the outer frame 84 of the projected image when the projected image is projected onto the screen 85. When the outer frame 84 is enlarged or reduced in accordance with the frame, the concave lens 61 is operated in conjunction with the movement of the movable lens 91, so that the laser unit is positioned at three points near the outer frame 84 of the enlarged or reduced projection image. The irradiation position of the laser beam from 58 will fluctuate. As a result, the distance from the three points located in the vicinity of the outer frame 84 of the projected image can always be measured, so that the accurate inclination of the screen 85 can be measured.

  According to the distance measuring device 15 in the present embodiment, by including an optical element that changes the direction of the laser beam emitted from the laser unit 58, the measurement point on the screen 85 surface for measuring the distance can be changed. .

  Further, in the distance measuring device 15, one light receiving element 56 is disposed at the center of the three laser units 58, and the irradiation direction of the three laser beams is changed by the optical element in a direction in which the interval is increased. Even when an image is projected using the zoom function in the projector 1, a laser beam can be irradiated in the vicinity of the outer frame 84 of the projected image projected on the screen 85, and the reflected light from these irradiation points can be Since the light receiving element 56 can receive light, it is not necessary to provide a plurality of light receiving elements, and it is not necessary to control each laser unit 58 individually, so that the distance measuring device 15 that is inexpensive and can vary the measurement point is provided. Can be provided.

  Furthermore, in the distance measuring device 15, by using a concave lens 61 whose distance from the laser unit 58 is variable as an optical element, the irradiation position of the laser beam emitted from the laser unit 58 is continuously moved by moving in the front-rear direction. Therefore, the distance from an appropriate measurement point can be measured according to various projection situations.

  In addition, since the distance measuring device 15 includes the measurement position adjusting unit 52 that operates the optical element, the operation of the concave lens 61 can be easily controlled.

  Since the projector 1 in the present embodiment includes the distance measuring device 15 as described above, the measurement point on the screen 85 surface for measuring the distance can be changed. Therefore, in the projector having a zoom function or the like, An accurate inclination of the screen 85 can be calculated regardless of the zoom magnification. Therefore, accurate keystone correction is always possible regardless of the distance from the screen 85 and the projection situation.

  In addition, the measurement position adjustment unit 52 operates the concave lens 61 as an optical element in accordance with the movement of the movable lens 91 of the projection side optical system, so that the measurement point can be obtained without searching for the measurement point from the projected image at the time of projection. Since it can be determined, the distance measuring device 15 can be easily controlled.

  In the above-described embodiment, the movable lens 91 and the concave lens 61 are operated in conjunction with the gear box 65, but the concave lens 61 can be separately driven by a motor or the like.

  Also, when a convex lens is used instead of the concave lens 61, the distance between the laser units 58 can be changed by changing the distance between the three laser beams emitted from each laser unit 58, thereby changing the distance on the screen. It is possible to adjust the distance between the irradiation positions of the respective laser beams applied to.

  Next, another embodiment of the present invention will be described. As shown in FIGS. 6 and 7, the distance measuring device 15 in another embodiment of the present invention is formed of a distance measuring unit 51 and a measurement position adjusting unit 52 as in the above-described embodiment. The measurement unit 51 includes a distance measuring substrate 55, a light receiving element 56, a light receiving barrel 57, and three laser units 58a and 58b arranged radially on the periphery of the light receiving barrel 57 in the same manner as the above-described embodiment. , 58c, a light receiving lens 59, and a prism lens 111 as an optical element that rotates so as to be sequentially positioned in front of an arbitrary laser unit 58a, 58b, 58c.

  The measurement position adjusting unit 52 in this embodiment includes a rotatable distance measuring lens barrel 112 that fixes the prism lens 111, and a distance measuring lens barrel 112 that is slidably held. A main barrel 113 and a rotation control device 114 for controlling the rotation of the distance measuring lens barrel 112 are provided.

  The prism lens 111 is arranged on the optical axis of the three laser units 58a, 58b, and 58c, and is adjacent to the two sector prisms 111b and 111c having different refraction angles with the inner angle being 120 degrees in the circumferential direction. It is formed by being arranged, and is stuck and fixed inside the distance measuring lens barrel 112. The prism lens 111 sequentially changes the irradiation position on the screen of the light emitted from the three laser units 58a, 58b, and 58c by rotating by 120 degrees.

  The distance measuring lens barrel 112 has a prism lens 111 as an optical element fixed in the vicinity of the front end thereof, and teeth that mesh with a rotation support gear 123 described later are formed on the outer peripheral edge. The lens barrel 113 is rotatably disposed inside. In addition, a fan-shaped flat glass 111a having a central angle of 120 degrees is disposed at a place where the two fan-shaped prisms 111b and 111c are not located.

  Therefore, the laser beam transmitted through the flat glass 111a maintains the irradiation direction from the laser units 58a, 58b, and 58c, but the laser beam transmitted through the fan-shaped prism with a small refraction angle is slightly refracted to the outside, and the laser beam The laser beam irradiated in the direction in which the mutual interval is widened and transmitted through the fan-shaped prism having a large refraction angle is refracted to the outside and irradiated in the direction in which the mutual interval of the laser beams is further expanded.

  The distance measuring main lens tube 113 holds the distance measuring lens tube 62 so as to be slidable, and has a through hole through which the rotation support gear 123 is inserted at a predetermined position. .

  The rotation control device 114 includes a distance measuring motor 121, a motor gear 122 attached to the rotation shaft of the distance measuring motor 121, and a rotation support gear 123 that meshes with the motor gear 122. The gear 123 passes through the insertion hole of the distance measuring lens barrel 113 and meshes with teeth formed on the outer wall of the distance measuring lens barrel 112 to rotate the distance measuring lens barrel 112. .

  Therefore, as shown in FIG. 8, the distance measuring device 15 irradiates the irradiation point 85a with the laser beam emitted from the laser unit 58a that irradiates the laser beam above the screen 85 via the flat glass 111a. In this case, the laser beam emitted from the laser unit 58b that passes through the flat glass 111a without changing the traveling direction and irradiates the laser beam on the lower left side of the screen 85 is removed from the traveling direction by the sector prism 111b. The laser beam emitted from the laser unit 58c that is refracted so as to bend and irradiates the irradiation point 85b and irradiates the laser beam to the lower right on the screen 85 surface is greatly increased outward by the sector prism 111c. It is refracted so as to be bent and is irradiated to the irradiation point 85c.

  When the distance measuring lens barrel 112 is rotated, the irradiation point of the laser beam emitted from the laser unit 58a changes in the order of the irradiation point 85a ′ and the irradiation point 85a ″. The laser beam emitted from 58b changes in the order of the irradiation point 85b ′ and the irradiation point 85b ″, and the laser beam emitted from the laser unit 58c changes in the order of the irradiation point 85c ′ and the irradiation point 85c ″. Therefore, the distance to a total of nine irradiation points can be measured.

  Further, as shown in FIGS. 6 and 7, the zoom mechanism 90 of the projection-side optical system in the projector 1 is located in the vicinity of the front end of the projection-side main barrel 93, and includes a movable lens 91 and a movable lens barrel. 92, a projection-side main barrel 93, and a projection-side ring 94 that can turn the periphery of the projection-side main barrel 93. A position search sensor 86 is disposed in the vicinity of the projection-side ring 94. It is what has been. Then, the movable lens 91 slides along the optical axis in the same manner as in the above-described embodiment, the position search sensor 86 confirms the position of the movable lens 91, and transmits the position information of the movable lens 91 to the projector control means. To do.

  The projector control means selects an appropriate irradiation point from the nine irradiation points irradiated by the laser units 58a, 58b, and 58c of the distance measuring device 15 based on the position information of the movable lens 91, and The keystone correction is performed by calculating the distance and the inclination angle.

  According to the present embodiment, the prism lens 111 is used as the measurement optical element, and the prism lens 111 is rotated, so that the irradiation direction of each laser beam is changed so as to be sequentially expanded or narrowed. Since the distance from the above nine points can be measured, the tilt of the screen 85 can be accurately calculated even when the projection magnification varies, and the accuracy of keystone correction can be increased.

  In addition, the prism lens 111 is rotated by the rotation control device 114 provided in the measurement position adjusting unit 52, and is emitted from the laser unit 58 and transmitted through the fan-shaped prisms 111b and 111c and the flat glass 111a and irradiated onto the screen 85. By calculating the distance from one point, the correct inclination of the screen 85 can be calculated.

  In addition, this invention is not limited to the above Example, A change and improvement are freely possible in the range which does not deviate from the summary of 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. The top view of the distance measuring device which concerns on the Example of this invention. Sectional drawing of the distance measuring device which concerns on the Example of this invention. The simplified perspective view which shows the state which inject | emitted the laser beam to the screen of the distance measuring device which concerns on the Example of this invention. The top view of the distance measuring device which concerns on the other Example of this invention. Sectional drawing of the distance measuring device which concerns on the other Example of this invention. The simple perspective view which shows the state which inject | emitted the laser beam to the screen of the distance measuring device which concerns on the other Example of this invention.

Explanation of symbols

1 Projector 11 Top plate
12 Front panel 13 Right panel
14 Projection port 15 Distance measuring device
16 Exhaust hole 18 Audio output
19 Air intake hole 20 Forefoot
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 control circuit 42 Lens motor
43 Cooling fan drive control circuit 45 Distance calculator
46 Inclination angle calculation unit 47 Distortion correction unit
48 Audio processor 49 Speaker
50 Display element 51 Distance measuring unit
52 Measurement position adjustment section 55 Distance measurement board
56 Light receiving element 57 Light receiving column
58 Laser unit 58a Laser unit
58b laser unit 58c laser unit
59 Receiving lens 61 Concave lens
62 Lens barrel for distance measurement 62a Cam pin for distance measurement
63 Main tube for distance measurement 64 Ring for distance measurement
65 Gearbox 66 Projection side gear
67 Distance measuring gear 80 Light source device
84 Outer frame
85 Screen 85a Irradiation point
85b Irradiation point 85c Irradiation point
86 Position search sensor 89 Movable lens group
90 Zoom mechanism 91 Movable lens
92 Movable lens barrel 92a Projection cam pin
93 Projection side main tube 94 Projection side ring
111 Prism lens 111a Flat glass
111b Fan-shaped prism 111c Fan-shaped prism
112 Lens tube for distance measurement 113 Main tube for distance measurement
114 Rotation control device 121 Distance measuring motor
122 Motor gear 123 Rotation support gear

Claims (8)

A frustoconical light receiving barrel having a wide opening side at the front and a narrow opening side at the rear, and three laser units that are arranged at equal intervals on the outer surface of the light receiving barrel and irradiate a laser beam forward;
A single light receiving element that receives reflected light from a distance measuring object at the center of the narrow opening side behind the light receiving barrel;
An optical element that changes the irradiation direction of each of the three laser beams irradiated from the laser unit in a direction that widens or narrows the distance between each other;
A distance measuring device comprising:   The distance measuring apparatus according to claim 1, wherein the optical element is a concave lens whose distance from the laser unit is variable.   The light receiving lens further includes a light receiving lens disposed so as to close an end of the light receiving lens barrel on the wide opening side, and three fan-shaped condensing lenses corresponding to the three laser units are disposed adjacent to each other in the circumferential direction. The distance measuring device according to claim 1. And said laser unit as distance measuring unit and the light receiving element which has the said optical element, the distance measurement according to claim 1 to claim 3, characterized in that it has a measuring position adjusting unit to operate the optical element apparatus. A light source device, a light source side optical system, a display element, a projection side optical system including a zoom mechanism, a projector control unit, a distance measurement device, an inclination angle calculation unit, and a distance calculation unit, and the distance measurement The projector is a distance measuring device according to any one of claims 1 to 3 . A light source device, a light source side optical system, a display element, a projection side optical system including a zoom mechanism, a projector control unit, a distance measurement device, an inclination angle calculation unit, and a distance calculation unit, and the distance measurement The projector is the distance measuring device according to claim 4. The projector according to claim 6 , wherein the measurement position adjustment unit operates the optical element in accordance with movement of a movable lens of the projection-side optical system. The optical element is a plurality of prisms having different refraction angles that are sequentially rotated to be positioned in front of the laser unit.
The measurement position adjustment unit rotates the optical element once at a constant rotation angle, and the distance calculation unit calculates a plurality of distances for each driving of the optical element by each laser unit. The projector according to claim 6 .

Images