JP4961923B2 - Projection device - Google Patents

Description

  The present invention relates to a projection apparatus that optically projects a projection image on a projection surface.

  2. Description of the Related Art Conventionally, a projection apparatus that enlarges and projects a projection image using modulated light modulated by a liquid crystal display panel, a digital micromirror device (DMD) or the like is known. When such a projection apparatus is used indoors, it is required to project a large projected image with a short projection distance to the projection surface. Therefore, a projection apparatus with a wide angle of view and a high resolution is required. Yes.

Therefore, for example, an image output apparatus using a digital micromirror device that controls the driving of the micromirror by a continuous pulse width modulation signal has been proposed (see Patent Document 1).
JP-A-11-266464

  However, in a conventional projection apparatus (image output apparatus), when a projection image is projected at a wide angle of view, an image projected on a location far from the optical axis of the projection lens is the optical axis of the projection lens. There is a problem that the light flux is smaller than that of an image projected on a location close to, and the brightness of the projected image is uneven.

  The present invention has been made in order to solve the above-described problems with simple means, and an object thereof is to provide a projection device that can easily perform image quality correction such as reduction in unevenness of brightness of a projected image. .

In order to solve the above-described problem, a projection apparatus according to a first aspect of the present invention generates a light source unit and white and chromatic light emitted from the light source unit according to the position of a pixel based on an image signal. In a projection apparatus comprising: a light modulation element that performs pulse width modulation according to a pixel signal to be projected; and a projection lens that magnifies and projects the modulated light emitted from the light modulation element onto a projection surface, the light based on the image signal A correction unit that corrects a pulse width of a pixel signal generated according to a pixel position of the modulation element, and the more the pixel position of the light modulation element is farther from the optical axis of the projection lens, the more white the modulated light Correction means for correcting the pixel signal corresponding to the pixel so as to increase the amount of increase due to correction of the luminous flux of the component or chromatic color component, and the presence of the modulated light with reference to the image signal or the pixel signal. Color component Determining means for determining whether or not the light flux amount is less than a predetermined value, and the correction means determines that the light flux amount of the chromatic component of the modulated light is less than a predetermined value by the determination means; The pixel signal is corrected so that the amount of increase due to correction of the luminous flux of the chromatic color component increases as the position of the pixel is farther from the optical axis of the projection lens, and the chromatic color component of the modulated light is determined by the determination means. Correction of the pixel signal to increase the amount of increase due to correction of the light flux of the chromatic color component as the pixel position is farther from the optical axis of the projection lens. It is characterized by not performing .
According to a second aspect of the present invention, there is provided a projection apparatus according to a pixel signal generated based on an image signal, and a light source unit and white and chromatic light emitted from the light source unit. And a projection lens for enlarging and projecting the modulated light emitted from the light modulation element onto the projection surface, based on the image signal, the pixel of the light modulation element A correction unit that corrects a pulse width of a pixel signal generated according to a position, and the farther the position of the pixel of the light modulation element is from the optical axis of the projection lens, the white component or chromatic color component of the modulated light. Correction means for correcting the pixel signal corresponding to the pixel so as to increase the amount of increase due to correction of the light flux, and the light flux amount of the chromatic component of the modulated light with reference to the image signal or the pixel signal Is not the predetermined value Determining means for determining whether or not the position of the pixel is the projection when the determining means determines that the luminous flux amount of the chromatic component of the modulated light is greater than or equal to a predetermined value. The farther from the lens optical axis, the pixel signal is corrected so as to increase the amount of increase due to the correction of the white component light beam, and the light amount of the chromatic component of the modulated light is less than a predetermined value by the determination means. When it is determined that the pixel signal is farther from the optical axis of the projection lens, the correction of the pixel signal that increases the amount of increase due to the correction of the light flux of the white component is not performed. To do.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the invention, the correction means may be configured such that the pixel position of the light modulation element is close to the optical axis of the projection lens. more, so as to enlarge the reduced amount of correction of the light beam chromatic components of said modulated light, and correcting the pulse width of the pixel signal.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the invention, the projection apparatus is a means for switching a correction method by the correction means, wherein the position of the pixel is from the optical axis of the projection lens. The brightness priority mode for correcting the pixel signal and the position of the pixel on the optical axis of the projection lens so as to increase the amount of increase due to the correction of the light flux of the white component or chromatic component of the modulated light as the distance increases. There is provided a mode switching means for switching between the color balance priority mode for correcting the pixel signal so as to increase the reduction amount due to the correction of the luminous flux of the chromatic component of the modulated light.

According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect of the invention, the projection apparatus obtains a projection distance that is a distance from the projection apparatus to a projection image projected onto the projection plane. An acquisition unit is provided, wherein the mode switching unit automatically switches between the brightness priority mode and the color balance priority mode according to the projection distance acquired by the projection distance acquisition unit.

The projection device of the invention according to claim 6, in addition to the configuration of the invention according to any one of claims 1 to 5, wherein the distance from the projector to the projected projection image on the projection plane projection distance The correction unit increases the amount of increase due to correction of the white component or the chromatic component of the modulated light as the projection distance acquired by the projection distance acquisition unit is longer. The pixel signal is corrected as follows.

According to a seventh aspect of the present invention, in addition to the configuration of the invention according to any one of the third to fifth aspects, a projection distance that is a distance from the projection apparatus to a projected image projected on the projection plane is provided. The correction unit is configured to increase the amount of decrease due to the correction of the luminous flux of the chromatic component of the modulated light as the projection distance acquired by the projection distance acquisition unit is shorter. The pixel signal is corrected.

The projection device of the invention according to claim 8, in addition to the configuration of the invention according to any one of claims 1 to 7, the brightness acquisition for acquiring a plurality of locations brightness of the projection image on the projection plane And the correction means expands the increase amount due to the correction of the white component or the chromatic color component of the modulated light that projects the spot as the brightness acquired by the brightness acquisition means decreases. The pixel signal is corrected.

The projection device of the invention according to claim 9, in addition to the configuration of the invention according to any one of claims 1 to 8, correction setting means for setting whether or not to correct the pixel signal by the correcting means It has.

Moreover, the projection device of the invention according to claim 1 0, in addition to the configuration of the invention according to any one of claims 1 to 9, wherein the correcting means generates a correction signal to be added to the pixel signal, said pixel The pixel signal is corrected by combining the signal and the correction signal.
The projection device of the invention according to claim 1 1, in addition to the configuration of the invention according to any one of claims 1 to 1 0, and performs multicolor display by the field sequential method.
Moreover, the projection device of the invention according to claim 1 2, in addition to the configuration of the invention according to any one of claims 1 to 1 1, wherein the light modulator, a digital micromirror device having a plurality of micromirrors It is characterized by becoming.
Moreover, the projection device of the invention according to claim 1 3, in addition to the configuration of the invention according to claim 1 2, wherein the correction means, characterized in that depending on the position of the micromirror, it corrects the pixel signal And

According to the projection device of the first aspect of the present invention, the correction device that corrects the pixel signal corresponding to the pixel of the light modulation element according to the position of the pixel of the light modulation element is provided. The pixel signal can be corrected so as to reduce unevenness. For this reason, it is possible to project a projection image with reduced brightness unevenness. Further, since the pixel signal corresponding to the pixel is corrected according to the position of the pixel of the light modulation element, it is easy to correct the image quality to reduce the unevenness of the brightness of the projected image. In addition, the pixel signal corresponding to the pixel is increased so that the amount of increase due to correction of the white component or chromatic component of the modulated light is increased as the position of the pixel of the light modulation element is farther from the optical axis of the projection lens. I am trying to correct it. For this reason, when correcting the pixel signal so as to increase the amount of increase due to the correction of the luminous flux of the white component of the modulated light, the brightness of the image projected at a location far from the optical axis of the projection lens increases, and the projection lens The brightness unevenness of the projected image projected on the projection plane can be reduced without impairing the brightness of the image projected on the position close to the optical axis. On the other hand, when correcting the pixel signal corresponding to a pixel so as to increase the amount of increase due to the correction of the luminous flux of the chromatic component of the modulated light, the vividness of the image projected on a location far from the optical axis of the projection lens The brightness unevenness of the projected image viewed by the user can be reduced while considering the color balance of the projected image.
In addition , when the amount of luminous flux for each chromatic color component is less than a predetermined value, the farther the pixel position of the light modulation element is from the optical axis of the projection lens, the greater the amount of correction due to correction of the luminous flux of the chromatic component of the modulated light The pixel signal corresponding to the pixel is corrected so as to enlarge the image. For this reason, it is possible to increase the brightness of an image far from the optical axis of the projection lens without destroying the color balance for a screen that is judged to be able to increase the chromatic color component, which is suitable for projection images. Correction can be performed automatically. In the case of intermittently projecting still images such as a slide show, it is particularly effective to optimize the sequential correction amount. In addition, when the amount of light flux for each chromatic color component is equal to or greater than a predetermined value, the pixel that increases the light flux of the chromatic color component of the modulated light as the position of the light modulation element pixel is further from the optical axis of the projection lens. The signal is not corrected. For this reason, it is possible to prevent a predetermined correction from being performed on a screen that is determined to be unable to increase the chromatic color component.
Further, according to the projection device of the invention according to claim 2 , since the correction device for correcting the pixel signal corresponding to the pixel according to the position of the pixel of the light modulation element is provided, the brightness generated in the projection image is provided. The pixel signal can be corrected so as to reduce the unevenness of thickness. For this reason, it is possible to project a projection image with reduced brightness unevenness. Further, since the pixel signal corresponding to the pixel is corrected according to the position of the pixel of the light modulation element, it is easy to correct the image quality to reduce the unevenness of the brightness of the projected image. In addition, the pixel signal corresponding to the pixel is increased so that the amount of increase due to correction of the white component or chromatic component of the modulated light is increased as the position of the pixel of the light modulation element is farther from the optical axis of the projection lens. I am trying to correct it. For this reason, when correcting the pixel signal so as to increase the amount of increase due to the correction of the luminous flux of the white component of the modulated light, the brightness of the image projected at a location far from the optical axis of the projection lens increases, and the projection lens The brightness unevenness of the projected image projected on the projection plane can be reduced without impairing the brightness of the image projected on the position close to the optical axis. On the other hand, when correcting the pixel signal corresponding to a pixel so as to increase the amount of increase due to the correction of the luminous flux of the chromatic component of the modulated light, the vividness of the image projected on a location far from the optical axis of the projection lens The brightness unevenness of the projected image viewed by the user can be reduced while considering the color balance of the projected image.
In addition, when the amount of luminous flux for each chromatic color component is equal to or greater than a predetermined value, the amount of increase due to correction of the luminous flux of the white component of the modulated light increases as the pixel position of the light modulation element is further from the optical axis of the projection lens. The pixel signal corresponding to the pixel is corrected so as to be enlarged. For this reason, it is possible to increase the brightness of the image far from the optical axis of the projection lens, reduce the unevenness of the brightness of the projection image projected on the projection surface, and automatically perform correction suitable for the projection image. It can be carried out. Further, it is possible to perform correction on a screen that is determined to be unable to increase the chromatic color component. On the other hand, when the amount of luminous flux for each chromatic color component is less than a predetermined value, the pixel signal that greatly increases the luminous flux of the white component of the modulated light as the pixel position of the light modulation element is farther from the optical axis of the projection lens The correction is not performed.

According to the projection device of the invention of claim 3 , in addition to the effect of the invention of claim 1 or 2 , the closer the position of the pixel of the light modulation element is to the optical axis of the projection lens, the more the modulated light. The pixel signal corresponding to the pixel is corrected so as to increase the amount of decrease due to the correction of the luminous flux of the chromatic component. Therefore, the closer the pixel position of the light modulation element is to the optical axis of the projection lens, the more the chromatic component is reduced, thereby reducing unevenness in the brightness of the projected image while placing importance on the color balance of the projected image. Can do.

In addition to the effect of the invention according to the third aspect , the projection apparatus according to the fourth aspect further includes mode switching means capable of switching between the brightness priority mode and the color balance priority mode. Therefore, the pixel signal correction method can be switched according to the user's preference.

Further, according to the projection device of the invention according to claim 5 , in addition to the effect of the invention of claim 4 , the mode is automatically switched according to the projection distance. An appropriate correction method can be automatically selected.

In general, in a projected image, the longer the projection distance, the less the luminous flux and the lower the brightness. On the other hand, according to the projection device of the invention according to claim 6 , in addition to the effect of the invention according to any one of claims 1 to 5 , correction of the light flux of the white component or the chromatic component as the projection distance becomes longer. Since the pixel signal is corrected so as to increase the amount of increase due to the above, it is possible to perform correction in consideration of the projection distance.

According to the projection device of the invention of claim 7 , in addition to the effect of the invention of any of claims 3 to 5 , as the projection distance becomes shorter, the reduction amount due to correction of the luminous flux of the chromatic color component is expanded. Since the pixel signal is corrected so as to be corrected, it is possible to perform correction in consideration of the projection distance.

Further, according to the projection device of the invention according to claim 8 , in addition to the effect of the invention according to any one of claims 1 to 7 , the light flux of the white component or the chromatic component as the brightness of the projected image decreases. Since the pixel signal is corrected so as to increase the amount of increase due to the correction, it is possible to perform appropriate correction according to the brightness of the projected image. Note that various parameters such as brightness, illuminance, and luminous flux can be employed as the brightness index of the present invention.

In addition to the effect of the invention according to any one of claims 1 to 8 , the projection apparatus according to the invention according to claim 9 includes a correction setting unit that sets whether or not to perform correction by the correction unit. Therefore, the user can execute correction processing as necessary.

Further, according to the projection apparatus of the invention according to claim 1 0, in addition to the effect of the invention according to any one of claims 1 to 9, correction means generates a correction signal to be added to the pixel signal, a pixel signal And the correction signal are combined to correct the pixel signal. For this reason, the pixel signal can be corrected without performing complicated processing.
Further, according to the projection apparatus of the invention according to claim 1 1, in addition to the effects of the invention according to any one of claims 1 to 1 0, without the need for color filters the light from the light source unit to modulate Since there is no color filter, there is no loss of light absorption, and the transmittance can be increased. For this reason, the utilization efficiency of the modulated light emitted by the projection device can be increased.
Further, according to the projection apparatus of the invention according to claim 1 2, in addition to the effect of the invention according to any one of claims 1 to 1 1, as the light modulation device, a digital micromirror device having a plurality of micromirrors Therefore, it is possible to obtain a high-definition, high-brightness, high-quality projected image even for still images and moving images.
Further, according to the projection apparatus of the invention according to claim 1 3, in addition to the effect of the invention according to claim 1 2, in accordance with the position of the micro-mirrors corresponding to the position of the pixel of the light modulation element, a pixel signal It can be corrected. In a projection apparatus equipped with a digital micromirror element as a light modulation element, there is a corresponding pixel signal for each micromirror, so by correcting the pixel signal according to the position of the micromirror, which signal is corrected how. You can easily determine what to do. Usually, the pixel angle, which is the angle formed by the modulated light corresponding to the micromirror and the optical axis of the projection lens, is determined by the position of the micromirror, so by correcting the pixel signal according to the position of the micromirror, Indirectly, the pixel signal can be corrected according to the pixel angle corresponding to the micromirror. Therefore, it is possible to project a projection image with reduced brightness unevenness by simple processing without storing the pixel angle of each micromirror or detecting the pixel angle of modulated light. .

  Hereinafter, as an example to which the present invention is applied, first and second embodiments will be described in order with reference to the drawings. First, the external appearance of a desktop projection apparatus 10 (hereinafter simply referred to as “projection apparatus 10”), which is the projection apparatus of the first embodiment of the present invention, will be described with reference to FIG. FIG. 1 is a left side view of the projection apparatus 10. As shown in FIG. 1, the projection apparatus 10 is used by being placed on a horizontal table 11, and projects a projection image onto a screen 51 provided on a wall surface. As shown in FIG. 1, the projection device 10 is a support member placed on the table 11 with the projection device main body 14 facing the direction of a screen 51 provided with a projection opening 15 on a vertical wall surface. The main body side fitting portion 13 having a square shape provided on the right side surface and the left side surface of the projection device main body 14 is placed on the support fitting portion 16 of the projection device 12 from above, thereby supporting the main body side fitting portion 13. The projection device main body 14 is supported at a predetermined height by being dropped into the fitting portion 16 and fixed at a position where an image is projected onto the screen 51 on the front wall surface. The projection device 10 can project an image on a screen such as the surface of the table 11, a wall surface perpendicular to the table 11, or a ceiling surface by changing the body-side fitting portion 13.

  Next, the functional configuration of the projection apparatus according to the first embodiment will be described with reference to FIG. FIG. 2 is a conceptual diagram showing a functional configuration of the projection apparatus 10. As shown in FIG. 2, the projection apparatus 10 includes an input unit 25, a frame memory 24, a microcomputer unit 23 including a CPU 230, a ROM 231, a RAM 232 and an EEPROM 233, a luminance measuring unit 21, a distance detecting unit 22, an image processing unit 32, a pulse. A width control unit 33, an optical element drive unit 34, and a lamp control circuit 41 are provided, and these are connected to each other by a bus 61. In addition, the projection apparatus 10 includes an image signal input unit 31 that inputs an image signal of a projection image projected on the screen 51 to the image processing unit 32, a lamp 42 as a light source controlled by the lamp control circuit 41, and an illumination optical system. 43, a light modulation element 44 formed of a digital micromirror element, and an imaging optical system 45 that forms an image on the screen 51 of the modulated light emitted from the light modulation element 44. Hereinafter, each configuration of the projection apparatus 10 will be described in detail.

  The CPU 230 of the microcomputer unit 23 performs main control of the projection apparatus 10 and executes various calculations and processes related to the operation and settings of the projection apparatus 10 according to a control program stored in the ROM 231 that is a read-only storage element. is there. Further, various calculations and processes are executed in accordance with the brightness correction program characteristic of the present invention stored in the ROM 231. The RAM 232 is an arbitrarily readable / writable storage element, and various storage areas are provided as needed to accommodate the calculation results calculated by the CPU 230. The brightness correction program may be stored in an external storage device such as a flexible disk or a memory card. In this case, the program is read into the RAM 232 and executed. The EEPROM 233 is a readable / writable nonvolatile storage element, and stores various settings, parameters, and the like related to the operation of the projection apparatus 10.

  The input unit 25 includes an input device such as an operation panel or a remote controller, and performs operation control, operation stop control, and the like of the projection device 10 when operated by a user. The input means 25 includes a luminance measurement mode key for setting the luminance measurement mode, a luminance measurement key for instructing luminance measurement, a cancel key for instructing to drive the projection apparatus 10 in the normal mode, and driving the projection apparatus in the correction mode. Various inputs such as a correction mode key for instructing to perform, a color instruction key for instructing a color for measuring luminance, an automatic correction key for selecting whether or not to perform correction in an automatic correction mode, and a mode selection key for selecting a correction method A selection key is provided as required.

  The image signal input unit 31 inputs an image signal input from the outside of the projection apparatus 10 to the image processing unit 32. The image processing unit 32 generates a waveform for controlling the light modulation element with respect to the input image signal based on the control by the CPU 230. The image signal generated in this way is input to the pulse width control unit 33 and the optical element drive unit 34 as a pixel signal. The pulse width control unit 33 generates a correction signal for correcting the pixel signal output from the image processing unit 32 in the correction mode for correcting the pixel signal. These pixel signals and the correction signal output from the pulse width control unit 33 are combined in the optical element drive unit.

  The lamp 42 is lighted and emits light based on an output signal from the lamp control circuit 41 controlled by the CPU 230 in accordance with a program stored in a predetermined storage area of the ROM 231. The light emitted from the lamp 42 is irradiated to the light modulation element 44 as illumination light by the illumination optical system 43.

  The illumination optical system 43 includes a lens group that collects the light emitted from the lamp 42. The illumination optical system 43 further includes a mirror on the light modulation element side as necessary. The mirror is provided at a predetermined angle in order to illuminate the light modulation element with light emitted from the lens group. In addition, a color wheel (not shown) including color filters of a total of four colors, red, blue corresponding to the chromatic color of the present invention, green, and white corresponding to the white color of the present invention, includes the illumination optical system 43 and the light. It is provided between the modulation element 44.

  The light modulation element 44 is a digital micromirror element that is driven by the control of the optical element drive unit 34 to display an image, and includes at least a micromirror that is a minute mirror corresponding to one pixel of a projection image. The number of micromirrors is aligned according to the number of pixels, and light that has passed through any color filter of the color wheel is incident on these micromirrors during projection. On the other hand, the optical element drive unit 34 is based on the pixel signal output from the image processing unit 32 in the normal mode in which the pixel signal is not corrected, and is output from the image processing unit 32 in the correction mode in which the pixel signal is corrected. Based on the corrected pixel signal obtained by synthesizing the pixel signal before correction and the correction signal generated by the pulse width control unit 33, the inclination of each micromirror is controlled, and the direction of the modulated light emitted from the micromirror The modulated light that enters the imaging optical system 45 is controlled by “ON” that makes the direction incident on the imaging optical system 45 and “OFF” that makes the direction different from the ON direction. The light modulation element 44 is not limited to a digital micromirror element, and for example, a reflection type liquid crystal element represented by LCOS may be used.

  The imaging optical system 45 is mainly composed of a plurality of lenses including a projection lens 451 (see FIG. 4). The imaging optical system 45 has an optical axis 70 perpendicular to the screen 51, and a plurality of lenses provided in the imaging optical system 45 are arranged in a line along the optical axis 70. The imaging optical system 45 projects the modulated light incident from the light modulation element 44 onto the screen 51 and forms a projected image on the screen 51.

  The luminance measuring unit 21 includes a luminance sensor that measures a plurality of luminances of the projected image projected on the screen 51 at least in a predetermined direction of the projected image as a unit for measuring the brightness of the projected image. As this luminance sensor, for example, an area sensor such as a CCD is used. The distance detection unit 22 includes a distance sensor that detects the distance between the projection device 10 and the screen 51. As this distance sensor, for example, an infrared sensor, an ultrasonic sensor or the like is used.

  The above projection apparatus 10 has a function as a projection apparatus according to the present invention, and correction for correcting pixel signals in order to reduce brightness unevenness of a projected image projected onto the screen 51 by the projection apparatus 10. It has a function.

  Next, using the projection device 10 configured as described above, the luminance correction amount C is obtained according to the luminance of the projection image projected onto the screen 51 by the projection device 10, and according to the position of the micromirror, A correction process for correcting the pixel signal will be described with reference to FIGS. FIG. 3 is an explanatory diagram schematically showing the micromirror group 440 included in the light modulation element 44. FIG. 4 shows the modulated light emitted from the micromirror group 440 passing through the projection lens 451 and projected onto the screen 51. It is explanatory drawing which shows typically the state performed. Further, FIG. 5 is based on a projection angle obtained by projecting the pixel angle which is an angle formed by the modulated light emitted from the projection apparatus 10 and the optical axis 70 of the imaging optical system 45 and the modulated light whose pixel angle is 0 degree. 6 is an example of a graph representing a relationship with a luminance ratio of a projection image obtained by projecting modulated light at each pixel angle. FIG. 6 is a timing chart for explaining a pixel signal before correction, a correction signal, and a pixel signal after correction obtained by combining the pixel signal before correction and the correction signal according to the first specific example. FIG. 7 is an explanatory diagram for explaining various settings related to the correction processing stored in the EEPROM 233 of the projection apparatus 10.

  FIG. 8 is a main flowchart showing the flow of the main processing of the first embodiment, and FIG. 9 is a flowchart of a subroutine showing the flow of luminance measurement processing executed in the main processing shown in FIG. FIG. 10 is a flowchart showing a flow of correction processing executed in the main processing shown in FIG. 8, and FIG. 11 is a flowchart showing a flow of brightness priority processing executed in the correction processing shown in FIG. . FIG. 12 is a graph showing the relationship between the pixel angle of the image projected according to the corrected pixel signal shown in FIG. 6 and the luminance ratio of the projected image on which the modulated light at each pixel angle is projected. FIG. 13 is a timing chart for explaining the pixel signal before correction, the correction signal, and the pixel signal after correction obtained by combining the pixel signal before correction and the correction signal according to the second specific example. FIG. 14 is a timing chart for explaining a pixel signal before correction, a correction signal, and a pixel signal after correction obtained by combining the pixel signal before correction and the correction signal according to specific example 3. FIG. 15 is a graph showing the relationship between the pixel angle and the luminance ratio of the projected image onto which the modulated light at each pixel angle is projected according to the corrected pixel signal shown in FIG. In order to simplify the description, pixel signals that are turned on when the color of the color filter is red will be described as an example with reference to the timing charts of FIGS. 6, 13, and 14. Accordingly, other colors are similarly controlled. A program for executing the correction processing according to the first embodiment is stored in the ROM 231 illustrated in FIG. 2 and is executed by the CPU 230.

  First, the micromirror group 440 provided in the light modulation element 44 of the projection apparatus 10 will be described with reference to FIG. As shown in FIG. 3, in the first embodiment, in order to simplify the description, the light modulation element 44 includes nine micromirrors, and each micromirror forms one pixel. Among the micromirror groups 440, the micromirror group 441 including the micromirrors M11, M12, and M13 includes each micromirror and the optical axis 70 on the side close to the optical axis 70 of the imaging optical system 45 shown in FIG. They are aligned so that the distance to the horizontal plane is the same. Further, the micromirror group 442 composed of the micromirrors M21, M22, and M23 is arranged on the side next to the optical axis 70 of the imaging optical system 45 and next to the micromirror group 441, with each micromirror and a horizontal plane including the optical axis 70. Aligned so that the distance is the same. Further, in the micromirror group 443 composed of the micromirrors M31, M32, and M33, the distance between each micromirror and the horizontal plane including the optical axis 70 is the same at the end far from the optical axis 70 of the imaging optical system 45. Aligned. As described above, the inclinations of the nine micromirrors of the micromirror group 440 are each controlled by the optical element drive unit 34 shown in FIG. 2 based on the pixel signal. In the first embodiment, the pixel angles corresponding to the respective micromirrors are regarded as having the same pixel angle as the micromirrors having the same distance from the horizontal plane including the optical axis 70, and are positioned at the positions of the micromirrors. Accordingly, the pulse width of the correction signal is determined. The same correction signal is generated for pixel signals corresponding to micromirrors that are considered to have the same pixel angle. For this reason, the correction signal according to the pixel angle is indirectly generated by determining the pulse width of the correction signal according to the position of the micromirror.

  Next, the relationship between the micromirror group 440 shown in FIG. 3 and the projection image will be described with reference to FIG. FIG. 4 schematically shows only the micromirror group 440 and the projection lens 451 among the components of the projection apparatus 10 in order to show the relationship between the micromirror group 440 and the projection image. As shown in FIG. 4, the optical axis 70 of the projection lens 451 is disposed so as to be perpendicular to the projection surface 50 of the screen 51, and the modulated light emitted by the micromirror group 440 is image forming optics. The light passes through the system 45 and is projected onto the projection surface 50 of the screen 51 to form a projected image. Of the micromirror group 440, the modulated light emitted by the micromirror group 441 near the optical axis 70 is projected onto the region 541 on the screen 51. Similarly, the modulated light emitted from the micromirror group 442 is projected onto a region 542 on the screen 51, and the modulated light emitted from the micromirror group 443 is projected onto a region 543 on the screen 51.

  If the image projected on the projection surface 50 of the screen 51 does not correct the pixel signal, the modulated light emitted from the projection device 10 and the optical axis 70 of the imaging optical system 45 are shown in FIG. The larger the pixel angle is, that is, the more the image projected onto the area away from the optical axis 70, the lower the luminance ratio, and the darker the brightness of the projected image is felt. In FIG. 4, the image projected on the region 543 is less bright than the image projected on the region 541, that is, it feels darker.

  Next, pixel signals for projecting a projection image will be described with reference to FIG. The projection device 10 synchronizes with the control of the angle of each micromirror of the micromirror group 440, and passes the light that has passed through the color filter of any one of red, green, blue, and white included in the color wheel. The micromirror is irradiated in a time-sharing manner to project a color projection image. For this reason, the pixel signal is obtained by dividing one screen period from T0 to T15 indicated by an arrow 71 in FIG. 6 according to the number of colors of the color filter, and each micromirror when light passing through each color is incident. Is indicated by a pulse signal. In FIG. 6, the relationship between one screen period divided into four (hereinafter simply referred to as “color period”) and the color of the color filter 73 is that the color of the color filter is red during the period from T0 to T4 (FIG. 6). In the period from T4 to T7, the color of the color filter 73 is green (“G” in FIG. 6), and in the period from T7 to T10, the color of the color filter 73 is blue (“B” in FIG. 6). ), During the period from T10 to T15, the color of the color filter 73 is white (“W” in FIG. 6). In consideration of the loss associated with the rotation of the color wheel, before and after the boundary of the color period, a period corresponding to T0 to T1, that is, T0 to T1, T3 to T5, T6 to T8, T9 to T11 In the period from T14 to T15, ON is not instructed.

  Then, from the start of the color period, that is, when the color of the color filter 73 is red, T1, when the color filter 73 is green, T5 when the color is green, and when the color of the color filter 73 is blue. In T8, a color period in which the color of the color filter 73 is white, a pulse signal instructing ON in each color period is generated from T11. For example, in the first specific example, the pixel signal 75 that controls the angle of the micromirror M11 before correction in FIG. 6 is the timing at which light that has passed through the red filter is incident, and from T1 to T2 in the red color period. It is instructed that the period is ON. In this way, the angle of each micromirror is instructed to be ON or OFF at the timing when the light that has passed through each color filter is incident by the pulse signal, and the angle of each micromirror is turned ON by the width of the pulse signal (Hereinafter simply referred to as “ON period”).

  Next, various settings related to the correction processing stored in the EEPROM 233 of the projection apparatus 10 will be described with reference to FIG. In the projection apparatus 10, it is assumed that various settings before turning on the power are set as shown in FIG. Hereinafter, each setting item will be described. “Luminance measurement mode” in FIG. 7 sets whether to measure the luminance of the image projected on the screen 51 before projecting the image based on the pixel signal, and “ON” for measuring the luminance. Alternatively, it is set by “OFF” in which the luminance is not measured, and is set to OFF in the specific example 1. The “brightness correction amount” stores whether or not the luminance correction amount is stored. In the first specific example, “YES” indicating that the luminance correction amount is stored is stored. The “correction mode” is used to set whether to correct the pixel signal in order to reduce unevenness in the brightness of the projected image. The correction mode is set to “ON” for correction or “OFF” for no correction. In specific example 1, it is set to ON. In addition, “all color measurement” is for setting whether or not the luminance is measured for all the colors of the color filter provided in the color wheel. “YES” for measuring the luminance for all colors or the luminance for only white. It is set by “NO” to be measured, and is set to YES in the specific example 1. In addition, the “automatic correction mode” is used to automatically determine the correction method used for the correction process and set whether to perform correction. “ON” for automatic determination or the correction method by the user In the specific example 1, it is set to ON. The “brightness priority mode” is used to set the correction method of the pixel signal, and is set by “ON” for correction in the brightness priority mode or “OFF” for correction in the color balance priority mode. In Example 1, it is set to ON. These settings are stored in the EEPROM 233, but other storage devices such as a flash memory and a memory card may be provided and stored there.

  Next, correction processing for correcting the pixel signal according to the position of the micromirror using the luminance correction amount C based on the luminance of the projection image projected onto the projection surface 50 of the screen 51 by the projection device 10 will be described with reference to FIGS. This will be described with reference to FIG. In the first embodiment, one of the three correction methods, that is, the position of the pixel of the light modulation element 44 is far from the optical axis 70 of the projection lens 451 depending on the setting and the characteristics of the pixel signal (the pixel angle is “White correction” and “color correction”, which are processes in the brightness priority mode for reducing brightness unevenness by increasing the brightness of a large area, and the pixel position of the light modulation element 44 are the positions of the projection lens 451. The pixel signal is corrected by any one of “color balance priority processing” that reduces the brightness unevenness by reducing the brightness of the portion close to the optical axis 70 (small pixel angle). Among these processing methods, first, as specific example 1, priority is given to the brightness of the projection image, the white component light flux for forming the projection image is adjusted, and the pixel signal before correction shown in FIG. A case will be described in which white correction is performed in accordance with the brightness of the projected image projected on the projector 51.

  In the main flowchart shown in FIG. 8, first, when the power of the projection apparatus 10 is turned on by the user, the EEPROM 233 is referred to and it is determined whether or not the brightness measurement mode is set (S10). This process is a process for determining whether to measure the luminance of an image (test pattern or the like) projected on the screen 51 before projecting the image based on the pixel signal. The luminance is predicted by the characteristics of the imaging optical system 45 when the pixel signal may be corrected using a luminance correction amount based on the already measured luminance, such as when the projector 10 is used at a fixed position. In some cases, such as when the luminance correction amount can be determined in advance, the luminance need not be measured every time the projection apparatus 10 is activated. In some cases, the projection apparatus 10 may be operated in a normal mode in which modulated light is projected based on uncorrected pixel signals. In such a case, the process of measuring the brightness can be omitted by setting the brightness measurement mode to OFF (S10: No). The ON / OFF setting of the luminance measurement mode may be set by the user using the input unit 25, or a predetermined condition is satisfied at the start of use or when the projection apparatus 10 is started up a predetermined number of times. In this case, it may be programmed to be automatically set so that the luminance measurement mode is turned on.

  In the first specific example, as shown in FIG. 7, it is determined that the luminance measurement mode is set to OFF (S10: No), and then the EEPROM 233 is referred to to determine whether the luminance correction amount C has already been set. Is determined (S20). In the first specific example, it is determined that the luminance correction amount C is set (S20: Yes). Subsequently, when the user presses the luminance measurement key included in the input unit 25 (S30: Yes), a new luminance is added. A measurement process is performed, and a process for obtaining a brightness correction amount based on the measured brightness is performed (S60). This process is a process for performing the brightness measurement process when it is determined that the user should reset the brightness correction amount even when the brightness measurement mode is set to OFF, and the brightness measurement key is pressed. It is. On the other hand, if the luminance measurement key has not been pressed (S30: No), it is determined that there is no need to reset the luminance correction amount, and therefore the user has not pressed the cancel key for a predetermined period (S40: No). , S50), it is determined that correction processing is performed using the already set luminance correction amount C. When the cancel key is pressed in S40 (S40: Yes), it is determined that it is instructed that no correction is necessary, and projection is performed in the normal mode based on the pixel signal to which no correction is applied (S100). If it is determined by this processing that the user does not need to project in the correction mode, the user can instruct to project in the normal mode by pressing the cancel key. If it is not necessary to give the user an opportunity to determine whether or not to project an image in the correction mode, this process (S40) may be omitted.

  Subsequent to S30 (S30: Yes), a luminance measurement process for obtaining the luminance correction amount C is performed (S60). This luminance measurement process will be described with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 9, first, the EEPROM 233 is referred to, and it is determined whether or not the luminance is set for all four colors of red, green, blue and white of the color filter provided in the light modulation element 44. (S610). Whether to measure the luminance of all the colors of the color filter may be set by the user using the input unit 25 or may be set by default. In S610, when not measuring all colors of luminance (S610: No), only the luminance of white is measured (S640). In the first specific example, as shown in FIG. 7, it is set that the luminance is measured for all colors (S610: Yes), and until it is determined that the luminance of all the colors has been measured (S630: Yes), the measurement of each luminance is performed. (S620).

  The luminance measurement method for each color in S620 will be described by taking as an example a case where the color filter included in the color wheel is red. First, the modulated light that has passed through the red color filter is projected onto the screen 51. The angle of the micromirror group 440 at this time is set to an “ON” state in which the emitted light is projected onto the screen 51. Subsequently, the luminance measuring unit 21 is operated to acquire a plurality of vertical luminances of the projected image projected on the screen 51. In the first embodiment, a plurality of directions in which brightness is measured are acquired in the vertical direction in which uneven brightness is easily visible to the user, but different directions are adopted depending on the uneven brightness of the projected image. Alternatively, the luminance in a plurality of directions may be measured, or the projected image may be divided into a plurality of blocks, and the luminance may be measured for each block. Further, the direction for measuring the luminance may be changed according to the color of the color filter. In the first specific example, a total of three luminances are measured for each of the areas 541 to 543 shown in FIG. This process measures the brightness of an image corresponding to a micromirror having a different distance from the optical axis 70 of the projection lens 451 in the projection image, and corresponds to the micromirror having the shortest distance from the optical axis 70 of the projection lens 451. This is a process for calculating the luminance correction amount C using the luminance ratio when the luminance of the image is 1. The luminance measurement method is the same for the white luminance measurement in S640.

  In the same manner, the luminance is measured for each color of the color filter (S620). If it is determined in S630 that the luminance has been measured for all colors (S630: Yes), the luminance is measured based on the luminance measured in S620 or S640. The luminance correction amount C is calculated (S650). If it is determined in S610 that all colors are measured (S610: Yes), the luminance correction amount C is obtained for each color measured in S620 (S650), and a predetermined storage area of the EEPROM 233 is obtained. (S660). When a plurality of correction methods can be adopted, a luminance correction amount C is obtained for each correction method (S650) and stored in a predetermined storage area of the EEPROM 233 (S660). In the first specific example, in order to simplify the description, when the correction method is white correction and color correction which will be described later with reference to FIG. In the color balance priority correction described later with reference to FIG. 10, the luminance correction amount C is calculated from C = X * (luminance ratio−0.8). However, “0.8” in the previous equation is a value designated by the user or the like, and the symbol “*” is a multiplication symbol. The luminance ratio of each color is the same as that when the color filter color is red, and the luminance correction amount C of each color is also the same.

  The calculation process of the luminance correction amount C will be described using the red luminance correction amount C when the correction method is white correction and color correction as an example. First, a luminance ratio is obtained based on the luminance of each color measured in S620. With this processing, for example, the luminance ratio of the region 541 is obtained as a reference, the luminance ratio of the region 541 is 1, the luminance ratio of the region 542 is 0.9, and the luminance ratio of the region 543 is 0.8. Subsequently, the reference value X for calculating the luminance correction amount C stored in the ROM 231 or the EEPROM 233 is acquired, and the luminance correction amount C added to the pixel signal for driving the micromirror corresponding to each pixel is obtained. , C = X * (1-luminance ratio). From the arithmetic processing according to this equation, the luminance correction amount C1 of the micromirror group 441 corresponding to the region 541 is 0, and the luminance correction amount C2 of the micromirror group 442 corresponding to the region 542 is 0.1X, corresponding to the region 543. The luminance correction amount C3 of the micromirror group 443 is calculated as 0.2X (S650). Subsequently, the luminance correction amount C is stored in a predetermined storage area of the EEPROM 233 in association with the position of the micromirror (S660). Similar processing is performed for other colors. Also, the luminance correction amount C used for the color balance priority correction is calculated by the same process. In this way, since the brightness correction amount C is calculated based on the brightness measured for each color, even when the brightness unevenness differs for each color, a correction signal is appropriately generated in accordance with the brightness unevenness of each color, and the projection image Brightness unevenness can be reduced.

  Subsequently, returning to the main process shown in FIG. 8, the EEPROM 233 is referred to, and it is determined whether or not the correction mode for correcting the pixel signal is set so as to reduce the uneven brightness of the projected image (S70). In the first embodiment, whether or not to perform the correction process is determined when the setting of the correction mode is stored in a predetermined storage area (S70: Yes) or within a predetermined period (S90). When the 25 correction mode key is pressed (S80: Yes), otherwise (S70: No, S80: No, S90), the image is projected in the normal mode without correcting the pixel signal (S100). . In the first specific example, it is determined that the correction mode ON is stored (S70: Yes), and subsequently, correction processing for correcting the pixel signal is performed (S110).

  The correction processing in S110 will be described with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 10, first, the EEPROM 233 is referred to and it is determined whether or not the automatic correction mode for automatically setting the correction method is set (S210). In the first embodiment, the brightness priority mode (S230) for performing brightness priority correction processing that prioritizes reducing the brightness unevenness of the projected image, and the brightness unevenness in consideration of the color balance of the projected image. The balance priority mode (S240) in which correction is performed with priority given to the balance to reduce the image quality can be selected, and it is selected in advance whether to apply correction to the pixel signal in any mode, and the automatic correction mode is set to ON. Thus (S210: Yes), every time the power is turned on, a preselected mode is automatically selected without selecting these modes (S220). On the other hand, even if the automatic correction mode is set to OFF, if any mode is selected by the user (S250: Yes), the pixel signal is corrected according to the selected mode ( S260). When the automatic correction mode is set to OFF (S210: No), the mode is not selected by the user (S250: No), and when the cancel key included in the input means 25 is pressed (S290: No). Yes), the image is projected in the normal mode without correcting the pixel signal (S300).

  In the first specific example, it is determined that the automatic correction mode is ON (S210: Yes) and the brightness priority mode is stored as ON (S220: Yes), and then brightness priority correction processing is performed (S230). The brightness priority correction process will be described with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 11, first, among the pixel signals corresponding to each micromirror, the position of the pixel of the light modulation element 44, that is, the position of the micromirror is the micromirror group 443 far from the optical axis 70 of the projection lens 451. For the corresponding pixel signal, it is determined whether a period for instructing to set the micromirror angle to OFF (hereinafter simply referred to as “OFF period”) is longer than the predetermined period Y (S231). This process is a process for determining whether or not the luminous flux amount of the chromatic component of the modulated light projected based on the pixel signal is less than a predetermined value. Here, it is assumed that the predetermined period Y is stored in the ROM 231 or the EEPROM 233 as being a half of the period from T1 to T3 shown in FIG. In S231, the OFF period when the color of the color filter of the pixel signal 77 corresponding to the micromirror M31 shown in FIG. 6 is red is the period from T2 to T4, and is determined to be shorter than the predetermined period Y. (S231: No). In this case, it is determined that the luminous flux amount of the chromatic component of the modulated light projected based on the pixel signal is equal to or greater than a predetermined value.

  In the processing of S231, the pixel signal corresponding to each micromirror of the micromirror group 443 of the predetermined number of screens is similarly examined, and the OFF period is set to the predetermined period Y for the pixel signal corresponding to any one of the micromirrors. When it is determined that there is the following color period (S231: No), following S231, in order to correct the uneven brightness of the projected image, the color of the color filter is white and the micromirror is turned on. White correction is performed to increase the light flux of the white component by turning on only for a period corresponding to the luminance correction amount C (S233). On the other hand, when it is determined that the OFF period is longer than the predetermined period Y for the pixel signals corresponding to all the micromirrors of the micromirror group 443 (S231: Yes), the modulation projected based on the pixel signals Since it is determined that the light flux amount of the chromatic component of the light is less than the predetermined value, a period corresponding to the luminance correction amount C at the timing when the color of the color filter is chromatic, which will be described later with reference to FIG. Color correction for increasing the luminous flux of the chromatic color component by turning on only is performed (S232). The number of screens referred to in S231 can be arbitrarily set according to the characteristics of the pixel signal.

  The white correction (S233) will be described. White correction is performed on the pixel signal corresponding to each micromirror read out for each screen period in the pulse width control unit 33 and the optical element drive unit 34. First, the pulse width controller 33 acquires the position of each micromirror, and based on the luminance correction amount C corresponding to the position stored in the EEPROM 233, a correction signal for turning on the micromirror at the timing when the color of the color filter is white. Is generated. For example, the luminance correction amount C1 corresponding to the micromirror M11 is 0, the luminance correction amount C2 corresponding to the micromirror M21 is 0.1X, and the luminance correction amount C3 of the micromirror M31 is stored as 0.2X. Therefore, correction signals 81 to 83 shown in FIG. 6 are generated as correction signals corresponding to the respective signals. The relationship between each correction signal and the luminance correction amount is that the correction signal 81 corresponds to the luminance correction amount 0, the color filter is not turned ON at the timing of white, and the ON period from T13 to T14 of the correction signal 82 is This corresponds to the luminance correction amount 0.1X, and the ON period from T12 to T14 of the correction signal 83 corresponds to the luminance correction amount 0.2X. Thus, the correction signal that greatly increases the ON period at the timing when the color filter is white is generated as the micromirror is located farther from the optical axis 70 of the projection lens 451. In the first embodiment, when executing white correction for increasing the luminous flux of the white component, the pulse is set so that the end of the correction signal is the end of the color period, that is, the end of the correction signal is T14. Is generated. On the other hand, as described above, the pixel signal before correction is generated from the start side of each color period, and thus correction is performed without complicated processing by determining the position where the correction signal is added. It is possible to avoid generating a correction signal during the same period as the pulse included in the previous pixel signal, and to add pulses regularly.

  Subsequently, the optical element drive unit 34 combines the pixel signal before correction output from the image processing unit 32 and the correction signal output from the pulse width control unit 33. By this processing, the pixel signal 75 corresponding to the micromirror M11 and the correction signal 81 are combined and corrected as a pixel signal 91. Similarly, the pixel signal 76 corresponding to the micromirror M21 and its correction signal 82 are combined and corrected as the pixel signal 92, and the pixel signal 77 corresponding to the micromirror M31 and its correction signal 83 are combined, The pixel signal 93 is corrected. By similar processing, pixel signals corresponding to other micromirrors are corrected. The corrected pixel signal for one screen is stored in the frame memory 24. If it is determined that white correction has been performed for all image periods, the white correction is terminated (S233). Then, the process returns to the flowchart shown in FIG. 10, and further returns to the main flowchart shown in FIG. 8, and the setting process ends. In the case where projection is continuously performed based on different image signals without turning off the power of the projection apparatus 10, the luminance measurement process (S60) shown in FIG. 8 is omitted, and the correction mode can be selected. The above processing may be performed, and when the pixel signal is corrected by the white correction similar to the first specific example, the processing may be performed from S233 shown in FIG.

  FIG. 12 shows the relationship between the pixel angle and the luminance ratio when an image is projected based on the pixel signal corrected by the brightness priority process detailed above. In FIG. 12, an image based on the pixel signals before and after correction 96 is projected, and the luminance of each pixel angle is based on the luminance of the projected image projected by the modulated light whose pixel angle before correction is 0 degrees. Seeking the ratio. As shown in FIG. 12, the post-correction 95 is improved in comparison with the pre-correction 96 under the condition that the pixel angle is large, that is, the degree to which the luminance ratio in the image projected on the location far from the optical axis 70 of the projection lens 451 is reduced. The Therefore, according to the brightness priority process of the first embodiment, an image with improved brightness unevenness can be projected.

  In addition, a correction signal to be added to the pixel signal is generated in the pulse width control unit 33, and the generated correction signal and the pixel signal are combined, and the light modulation element 44 is generated from an image signal input from the outside. The image processing unit 32 that generates a pixel signal for controlling each of the pixels is clearly distinguished from the pulse width control unit 33 that generates a correction signal. For this reason, it is possible to perform correction based on luminance unevenness and the like without affecting the control by the pixel signal, and it is possible to perform correction without performing complicated processing, and there is a control load for performing processing for correction. light. Furthermore, since the process for generating the correction signal can be performed separately, it is easy to change the specifications necessary for performing the correction process of the present invention.

  In specific example 1, in S231 shown in FIG. 11, the OFF period of the timing when the color of the color filter is red is the period from T2 to T4 in FIG. 6, and is determined to be shorter than the predetermined period Y ( S231: No), the white correction is performed to increase the luminous flux of the white component according to the position of the micromirror, but the micromirror group 433 as shown in the pixel signal 177 of the micromirror M31 of the specific example 2 shown in FIG. For the pixel signal corresponding to, the OFF period of the timing when the color of the color filter is red is the period from T22 to T25 in FIG. 13 and is determined to be longer than the predetermined period Y (S231: Yes), Since it is determined that the luminous flux amount of the chromatic component of the modulated light projected based on the pixel signal is less than the predetermined value, the color is different from the white correction that increases the luminous flux of the white component. A positive carry out (S232). This color correction will be described with reference to FIGS. The pixel signal of specific example 2 shown in FIG. 13 is the same as the pixel signal of specific example 1 shown in FIG.

  In the color correction, in order to eliminate the uneven brightness of the projection image, the priority is given to the brightness, and the color balance of the projection image is taken into consideration, and the position of the pixel of the light modulation element, that is, the position of the micromirror is the projection lens 451. This is a process of correcting the pixel signal so that the amount of increase due to the correction of the light flux of the chromatic component increases as the distance from the optical axis 70 increases. This color correction is executed in the pulse width control unit and the optical element drive unit 34 as in the white correction. First, in the pulse width control unit 33, the position of each micromirror is acquired, and based on the luminance correction amount C corresponding to the position of the micromirror stored in the EEPROM 233, the color of the color filter is the timing of the chromatic color. A correction signal for turning ON is generated. In the second specific example, ON is set only when the color of the color filter is a chromatic color, and only red is set, and green and blue are not set ON. Therefore, correction is performed in consideration of the color balance of the projection image. Therefore, the correction signal is generated only for the red color period in which the period set to ON exists in the color period.

  With this process, for example, the luminance correction amount C1 corresponding to the micromirror M11 is 0, the luminance correction amount C2 corresponding to the micromirror M21 is 0.1X, and the luminance correction amount C3 of the micromirror M31 is 0.2X. Therefore, correction signals 181 to 183 shown in FIG. 13 are generated as the correction signals corresponding to each of them. As in the case of white correction, the relationship between each correction signal and the luminance correction amount is not ON in the correction signal 181 corresponding to the luminance correction amount 0, and the luminance correction amount is in the ON period from T24 to T25 of the correction signal 182. This corresponds to 0.1X, and the ON period from T23 to T25 of the correction signal 183 corresponds to a luminance correction amount of 0.2X. Thus, depending on the position of the micromirror, the pixel position of the light modulation element, that is, the position of the micromirror is farther from the optical axis 70 of the projection lens 451. A correction signal for greatly increasing the ON period at the timing when the color filter is a chromatic color is generated. In the first embodiment, similarly to the white correction, the end of the correction signal of each color period is set to the end of the color period, that is, when the color filter is red in FIG. 13, the end of the correction signal. A pulse is generated so that becomes T25. Since the pixel signal before correction is generated from the start side of each color period as described above, the pixel signal before correction is added to the pixel signal by determining the position to add the correction signal in this way. And a correction signal to be distinguished. That is, the period in which the pixel signal is generated can be divided from the period in which the correction signal is added.

  Subsequently, the optical element drive unit 34 combines the pixel signal before correction output from the image processing unit 32 and the correction signal output from the pulse width control unit 33. By this processing, for example, the pixel signal 175 corresponding to the micromirror M11 and the correction signal 181 are combined and corrected as a pixel signal 191. Similarly, the pixel signal 176 corresponding to the micromirror M21 and its correction signal 182 are combined and corrected like the pixel signal 192, and the pixel signal 177 corresponding to the micromirror M31 and its correction signal 83 are combined, Correction is performed like a pixel signal 193. By similar processing, pixel signals corresponding to other micromirrors are corrected. The corrected pixel signal for one screen is stored in the frame memory 24. When it is determined that color correction has been performed for all image periods, the color correction is terminated (S234).

  According to the color correction described in detail above, the amount of increase due to the correction of the light flux of the chromatic component is increased in the projected image where the pixel position of the light modulation element, that is, the position of the micromirror is far from the optical axis 70 of the projection lens 451. By correcting the pixel signal so as to enlarge, the vividness of the image projected on a location far from the optical axis 70 of the projection lens 451 can be increased. For this reason, it is possible to reduce the uneven brightness of the projected image in consideration of the color balance of the projected image while giving priority to the brightness of the projected image.

  In specific example 1 and specific example 2, brightness priority correction processing is performed in the main processing shown in FIG. 10 (S230), but color balance priority correction is performed in consideration of the color balance of the projected image. It may be (S240). This color balance priority correction will be described with reference to FIGS. The pixel signal of specific example 3 shown in FIG. 14 is the same as the pixel signal of specific example 1 shown in FIG.

  Color balance priority correction corrects the pixel signal so that the amount of decrease due to correction of the light flux of the chromatic color component increases as the pixel position of the light modulation element, that is, the position of the micromirror is closer to the optical axis 70 of the projection lens 451. In addition, by controlling the vividness of the projected image where the pixel position of the light modulation element, that is, the position of the micromirror is close to the optical axis 70 of the projection lens 451, the brightness of the projected image is given priority to color balance. Unevenness is reduced. This color balance priority correction is executed in the pulse width control unit 33 and the optical element drive unit 34 as in the case of white correction and color correction. First, in the pulse width control unit 33, the position of each micromirror is acquired, and based on the luminance correction amount C corresponding to the position stored in the EEPROM 233, the micromirror is turned on at the timing when the color of the color filter is chromatic. A correction signal is generated to shorten the ON period, that is, to shorten the pulse width of the pixel signal. In specific example 3, as shown in FIG. 14, ON is set at the timing when the color of the color filter is a chromatic color, only red among the three chromatic colors, and the color of the color filter is green. And it is not turned ON at the timing of blue. Therefore, in order to perform correction in consideration of the color balance, a correction signal is generated that turns on the color filter in the ON period for a predetermined period at the red timing.

  With this process, for example, the luminance correction amount C1 corresponding to the micromirror M11 is 0.2X, the luminance correction amount C2 corresponding to the micromirror M21 is 0.1X, and the luminance correction amount C3 of the micromirror M31 is 0. Therefore, correction signals 281 to 283 shown in FIG. 14 are generated as the corresponding correction signals. The relationship between each correction signal and the luminance correction amount is that the ON period from T31 to T33 of the correction signal 281 corresponds to the luminance correction amount 0.2X, and the ON period from T31 to T32 of the correction signal 282 is the luminance correction amount 0. .1X, the correction signal 283 is not turned ON corresponding to the luminance correction amount 0. In the first embodiment, a pulse for reducing the width of the pixel signal is generated from the beginning of the period of the correction signal. As described above, since the pixel signal before correction is generated from the start side of each color period, the pixel signal before correction is included in each color period by determining the position where the pulse is added in this way. A correction signal for shortening the pulse width of the pixel signal before correction can be generated without determining in which period it was generated.

  Subsequently, the optical element drive unit 34 combines the pixel signal before correction output from the image processing unit 32 and the correction signal output from the pulse width control unit 33. By this processing, the pixel signal 275 corresponding to the micromirror M11 and the correction signal 281 are synthesized, and the ON period of the pixel signal 275 before correction is shortened by the ON period of the correction signal 281 so that the pixel signal 291 is obtained. It is corrected. Similarly, the pixel signal 276 corresponding to the micromirror M21 and its correction signal 282 are combined and corrected like the pixel signal 292, and the pixel signal 277 corresponding to the micromirror M31 and its correction signal 283 are combined, Correction is performed like a pixel signal 293. By similar processing, pixel signals corresponding to other micromirrors are corrected. As described above, depending on the position of the micromirror, the micromirror having a smaller corresponding pixel angle greatly reduces the ON period at the timing when the color filter is a chromatic color. The corrected pixel signal for one screen is stored in the frame memory 24. When it is determined that the color balance priority correction has been performed for all image periods, the color balance priority correction is terminated (S240).

  FIG. 15 shows the relationship between the pixel angle and the luminance ratio when an image is projected based on the pixel signal corrected by the color balance priority process detailed above. In FIG. 15, an image based on the pixel signals before correction 296 and post-correction 295 is projected, and the luminance of each pixel angle is based on the luminance of the projected image projected by the modulated light whose pixel angle before correction is 0 degrees. Seeking the ratio. As shown in FIG. 14, the post-correction 295 and the pre-correction 296 reduce the luminance ratio under the condition that the pixel angle is small, so that the condition where the pixel angle is large, that is, the pixel position of the light modulation element is the projection lens 451. Difference in luminance ratio between the condition far from the optical axis 70 and the condition where the pixel angle is small, that is, the condition where the pixel position of the light modulation element is close to the optical axis 70 of the projection lens 451 can be reduced. Unevenness of brightness is improved. Therefore, according to the color balance priority correction, an image with improved brightness unevenness can be projected while giving priority to the color balance of the projected image.

  In the projector 10 according to the first embodiment described above, the lamp control circuit 41 and the lamp 42 shown in FIG. 2 correspond to the light source unit of the present invention. 2 includes a plurality of micromirrors and a color wheel, and modulates the illumination light that has passed through the illumination optical system 43 based on the pixel signal. The light modulation element 44 shown in FIG. It corresponds to an element. Further, the input means 25 shown in FIG. 2 for setting whether or not to correct the pixel signal in S80 of the main flowchart shown in FIG. 8 corresponds to the correction setting means of the present invention.

  Further, in S231 of the flowchart shown in FIG. 11, it is determined whether or not the period for instructing to set the micromirror angle to OFF is shorter than a predetermined value with reference to the pixel signal corresponding to each micromirror. Thus, the CPU 230 shown in FIG. 2 that determines whether or not the amount of light of the chromatic component of the modulated light is less than a predetermined value corresponds to the determination means of the present invention. Further, in the flowchart shown in FIG. 11, it is determined that the OFF period for instructing to set the micromirror angle to OFF is longer than the predetermined period Y, and the luminous flux amount of the chromatic component of the modulated light is less than the predetermined value. (S231: Yes), color correction is performed (S232). Depending on the position of the micromirror, the position of the pixel of the light modulation element, that is, the position of the micromirror is farther from the optical axis 70 of the projection lens 451. The CPU 230 shown in FIG. 2 corrects the pixel signal by generating a correction signal so as to increase the increase amount due to the correction of the light flux of the chrominance component and combining the pixel signal before correction with this correction signal. It functions as the correction means of the invention. In the color balance priority correction in S240 or S280 of the flowchart shown in FIG. 10, the closer the position of the pixel of the light modulation element, that is, the position of the micromirror, is to the optical axis 70 of the projection lens 451, the light flux of the chromatic component of the modulated light. The CPU 230 shown in FIG. 2 that corrects the pixel signal so as to increase the amount of decrease due to the correction functions as a correction unit of the present invention.

  In S250 of the flowchart of FIG. 10, the amount of increase due to the correction of the white component of the modulated light is increased as the pixel position of the light modulation element, that is, the position of the micromirror is farther from the optical axis 70 of the projection lens 451. The brightness priority mode for correcting the pixel signal so that the pixel position of the light modulation element, that is, the position of the micromirror is closer to the optical axis 70 of the projection lens 451, and the correction of the luminous flux of the chromatic component of the modulated light. The input unit 25 shown in FIG. 2 that switches the color balance priority mode for correcting the pixel signal so as to increase the reduction amount corresponds to the mode switching unit.

  Further, the luminance measuring unit 21 shown in FIG. 2 that acquires a plurality of luminances as the brightness index of the projected image projected on the screen 51 corresponds to the brightness acquiring unit of the present invention. Further, in S233 shown in FIG. 11, the lower the luminance serving as the brightness index acquired by the luminance measuring unit 21 shown in FIG. 2, the increased amount due to the correction of the white component light flux of the modulated light that projects that location. The CPU 230 shown in FIG. 2, which generates a correction signal using a luminance correction amount determined to be enlarged and synthesizes the correction signal and the pixel signal to perform white correction, functions as a correction unit of the present invention. Further, in S232 shown in FIG. 11, the lower the luminance serving as the brightness index acquired by the luminance measuring means 21 shown in FIG. The CPU 230 shown in FIG. 2 that generates a correction signal so as to expand the color and color-corrects the correction signal and the pixel signal functions as a correction unit of the present invention.

  According to the projection apparatus 10 of the first embodiment described above, the correction device that corrects the pixel signal corresponding to the pixel according to the position of the pixel of the light modulation element, that is, the position of the micromirror is provided. Therefore, it is possible to correct the pixel signal so as to reduce the uneven brightness that occurs according to the position of the pixel of the light modulation element. For this reason, it is possible to project a projection image with reduced brightness unevenness. In addition, since the light modulation element 44 uses a digital micromirror element including a plurality of micromirrors, a high-definition, high-brightness, and high-quality projected image can be obtained even for still images and moving images. Note that since the position of the pixel of the light modulation element is defined according to the angle of view of the projection lens 451, the pixel signal may be corrected in consideration of the angle of view of the projection lens 451.

  Further, in the white correction for correcting the pixel signal so as to increase the amount of increase due to the correction of the white light flux of the modulated light in FIG. 11 (S233), the image projected on a position far from the optical axis 70 of the projection lens 451 is displayed. Brightness increases, and unevenness in the brightness of the projected image projected on the projection surface can be reduced. On the other hand, in color correction in which the pixel signal is corrected so as to increase the amount of increase due to correction of the luminous flux of the chromatic component of the modulated light (S232), the position of the pixel of the light modulation element 44, that is, the position of the micromirror is the projection lens 451. It is possible to increase the vividness of an image projected on a location far from the optical axis 70 and reduce the unevenness of the brightness of the projected image visually recognized by the user.

  Further, the projection apparatus 10 of the first embodiment automatically selects the white light correction or the color correction based on the luminous flux for each chromatic color component, so that the projection is performed. Correction suitable for an image can be automatically performed. Further, since the projection apparatus 10 includes the input unit 25 that can switch between the brightness priority mode (S230 or S270) and the color balance priority mode (S240 or S280), the user preference, the characteristics of the pixel signal, and the like. The correction method of the pixel signal can be switched according to the above.

  Further, in the color balance priority correction (S240 or S280), the projection apparatus 10 modulates an image projected on a position where the pixel position of the light modulation element 44, that is, the position of the micromirror is close to the optical axis 70 of the projection lens 451. The pixel signal is corrected so as to increase the amount of decrease due to the correction of the luminous flux of the chromatic component of the modulated light as the light increases. Therefore, the modulated light whose position of the pixel of the light modulation element 44, that is, the position of the micromirror is closer to the optical axis 70 of the projection lens 451, reduces the chromatic color component more, thereby giving importance to the color balance and placing importance on the color balance. Brightness unevenness can be reduced.

  In addition, the projection device 10 uses the luminance correction amount obtained by using the luminance corresponding to each color of the color wheel as the correction amount used when generating the correction signal. Since the pixel signal is corrected so as to increase the increase amount due to the correction of the luminous flux of the chromatic color component, appropriate correction can be performed according to the brightness of the projected image. In addition, since the projection apparatus 10 includes the input unit 25 for setting whether or not to correct the pixel signal, the user can execute correction processing as necessary. Since the projection device 10 corrects the pixel signal by generating a correction signal to be added to the pixel signal and combining the pixel signal and the correction signal when correcting the pixel signal. The pixel signal can be appropriately corrected without performing complicated processing.

  In addition, this invention is not limited to 1st Embodiment explained in full detail above, You may add a various change within the range which does not deviate from the summary of this invention. For example, although the desktop projector 10 has been described as the projector of the first embodiment, the projector is not limited to the desktop projector, and may be applied to a projector installed on a wall or ceiling. . Further, the configuration and appearance of the projection apparatus can be changed as appropriate.

  In the first embodiment, a digital micromirror element including a plurality of micromirrors is used as the light modulation element 44. However, the present invention is not limited to this, and a reflective liquid crystal such as LCOS is used as the light modulation element. An element may be used. Further, for example, a projection device driven by a field sequential method may be used. In the case of a projection device driven by a field sequential method, the projection device does not require a color filter, and since there is no filter, there is no absorption loss and the transmittance is high. In the first embodiment, the case where the number of micromirrors provided in the projection apparatus 10 is nine has been described for the sake of simplicity. However, the number, shape, and arrangement of the micromirrors can be variously changed. is there.

  Further, in the first embodiment, the brightness priority mode and the color balance priority mode are configured to be selectable, and the brightness priority mode is determined depending on whether the OFF period of the chromatic color component is longer than the predetermined period. Color correction or white correction is performed, and the three correction methods are selectively used according to settings and pixel signals. However, the present invention is not limited to this. For example, any one of these or any arbitrary Correction may be performed by two correction methods. In the brightness priority mode, white correction and color correction may be combined to correct the pixel signal so as to increase the amount of increase due to correction of both the white component and the chromatic component of the modulated light. .

  In the first embodiment, the luminance is used as the brightness index of the projected image. However, the present invention is not limited to this, and various parameters such as illuminance and luminous flux can be employed.

  In the first embodiment, the luminance correction amount C is determined based on the luminance of the projection image, and the correction signal is generated using the luminance correction amount C. However, the present invention is not limited to this. When the correction amount for correcting the brightness unevenness can be determined in advance according to the angle of view of the projection lens due to the lens characteristics provided in the optical system 45 (see FIG. 2), the correction signal is based on the correction amount. May be generated. In that case, the predetermined correction amount may be stored in a storage medium such as the ROM 231 or the EEPROM 233, and the correction amount may be referred to in the generation process of the correction signal. When the correction amount is determined in advance as described above, the process of measuring the brightness that is an index of brightness and calculating the correction amount used when generating the correction signal as in the first embodiment is omitted. Therefore, the apparatus configuration necessary for the correction process can be simplified, and the time required for the correction process can be shortened.

  In the first embodiment, a correction signal to be added to the pixel signal before correction is generated and the pixel signal before correction and the correction signal are combined to correct the pixel signal. Without being limited, the correction signal may be directly added to the pixel signal before correction. In the first embodiment, the start or end period for applying the correction signal pulse is determined according to the correction method. However, the present invention is not limited to this. For example, an arbitrary period in a predetermined color period. You may make it add a pulse to. When a digital micromirror element is used as the light modulation element as in the first embodiment, the number of ON periods included in one color period is determined in consideration of a loss when switching the angle of the micromirror. Less is preferable.

  In the first embodiment, in the brightness priority process illustrated in FIG. 11, the pixel signal of the micromirror group 433 in which the pixel position of the light modulation element 44, that is, the position of the micromirror is far from the optical axis 70 of the projection lens 451. , Whether to perform white correction or color correction is determined (S231). However, the pixel signal referred to in this processing is not limited to this. For example, the pixel of the light modulation element 44 The condition of the pixel signal to be referred to may be determined so as to refer to the pixel signal corresponding to the modulated light whose distance from the position to the optical axis 70 of the projection lens 451 is longer than a predetermined value, or all pixel signals are referred to. You may do it. In S231, the image signal input by the image signal input unit 31 may be referred to determine whether or not the luminous flux amount of the chromatic component of the modulated light is less than a predetermined value. In the case of referring to an image signal, the brightness of the image is obtained from the voltage value included in the image signal, so that the processing can be simplified. The predetermined period Y determined in S231 can be arbitrarily determined according to the characteristics of the pixel signal, the projection location, the user's preference, and the like. The predetermined period Y may be changed for each color of the color filter corresponding to the pixel signal, or may be changed according to the brightness of the projection image and the position in the projection image.

  In the second embodiment, when the OFF period is longer than the predetermined period Y in S231 shown in FIG. 11 (S231: Yes), the color correction is performed (S232). However, the present invention is not limited to this. Depending on whether the OFF time is equal to or shorter than the predetermined period J, it is determined that the luminous flux amount of the chromatic component of the modulated light projected based on the image signal or the pixel signal is equal to or larger than the predetermined value, and is determined to be equal to or shorter than the predetermined period J. In such a case, color correction may not be performed. In such a case, it is possible not to perform color correction on a screen that is determined to be unable to increase the chromatic color component.

  Next, a second embodiment for determining the reference value X used when calculating the luminance correction amount C according to the distance between the projection apparatus 10 and the projection surface 50 will be described with reference to FIGS. 16 and 17. . FIG. 16 is a main flowchart showing the flow of the main processing of the second embodiment, and FIG. 17 is a flowchart of a subroutine showing the flow of luminance measurement processing executed in the main processing shown in FIG. Note that the configuration of the projection apparatus 10 is the same as that of the first embodiment, and thus the description thereof is omitted. A program for executing correction processing according to the second embodiment is stored in the ROM 231 shown in FIG. 2 and is executed by the CPU 230.

  As shown in FIG. 16, the flow of the correction process according to the second embodiment is different from that of the first embodiment in S3, S5, and S65. A description of processing that is common to the first embodiment will be omitted, and S3, S5, and S65 different from the first embodiment will be described below.

  First, when the power is turned on, the distance detecting means 22 is operated, and the projection distance L between the projection apparatus 10 and the projection surface 50 is detected (S3). This process is a process for determining the reference value X used when calculating the luminance correction amount C according to the projection distance L. The projection distance L may be a distance that allows the positional relationship between the projection apparatus 10 and the projection plane 50 to be determined. For example, the shortest distance between the projection apparatus 10 and the projection plane 50 may be adopted. The distance between the projection device 10 and the center of the projection image may be employed. Subsequently, the projection distance L detected in S3 is stored in a predetermined storage area of the EEPROM 233 (S5).

  Next, luminance measurement processing (S65) different from the first embodiment will be described with reference to the flowchart shown in FIG. As shown in FIG. 17, the flow of the luminance measurement process is different from that of the first embodiment in S645, S655, and S665. The description of the processes common to the first embodiment is omitted, and the processes of S645, S655, and S665 different from the first embodiment will be described below.

  After the predetermined luminance is measured (S630: Yes or S640), the EEPROM 233 is referred to, and the projection distance L set in S5 of FIG. 16 is acquired (S645). Subsequently, the luminance correction amount C is calculated based on the luminance ratio calculated from the luminance measured in S620 or S640 and the reference value X determined according to the projection distance L acquired in S645 (S655). For the reference value X determined according to the projection distance L, for example, a linear relational expression is determined between the projection distance L and the reference value X and stored in the ROM 231 or the EEPROM 233 in advance, and the projection distance is calculated from the relational expression. A reference value X corresponding to L is obtained. In this relational expression, in the luminance correction amount used in the brightness priority mode, the luminance correction amount is greatly increased so that the increase amount due to correction of the white light component of the modulated light is increased as the projection distance L is longer. In the balance priority mode, it is determined that the increase amount due to the correction of the luminance correction amount is increased so that the increase amount due to the correction of the luminous flux of the chromatic color component is increased as the projection distance L is longer. Using the reference value X thus obtained, the luminance correction amount C is determined by, for example, C = X * (1−luminance ratio) as in the first embodiment (S655). Subsequently, the brightness correction amount C obtained in S655 is stored in the EEPROM 233 (S665).

  In the second embodiment, the correction signal is generated using the luminance correction amount C by the process described in detail above. The distance detection unit 22 shown in FIG. 2 that acquires the projection distance that is the distance from the projection device 10 to the projection image projected onto the projection plane 50 corresponds to the projection distance acquisition unit of the present invention. The longer the projection distance L acquired by the distance detection means 22, the more the pixel signal is corrected in the brightness priority mode so that the increase amount due to the correction of the white component of the modulated light is corrected. The CPU 230 shown in FIG. 2 that corrects the pixel signal so as to increase the amount of increase due to the correction of the luminous flux of the chromatic component corresponds to the correcting means of the present invention.

  According to the second embodiment described in detail above, the reference value X used when obtaining the luminance correction amount is the luminance correction amount used in the brightness priority mode. The brightness correction amount is greatly increased so as to increase the increase amount due to the correction of the luminous flux, and in the color balance priority mode, the brightness is increased so that the increase amount due to the correction of the chromatic color light flux is increased as the projection distance L is longer. Since the amount of increase due to correction of the correction amount is set to be enlarged, in general, the longer the projection distance, the less the luminous flux, and the unevenness of the brightness of the projected image, which decreases in brightness, is appropriately determined according to the projection distance. It can be reduced by using a proper luminance correction amount.

  The present invention is not limited to the second embodiment described in detail above, and various modifications may be made without departing from the scope of the present invention. For example, in the second embodiment, the luminance correction amount C is based on the luminance ratio calculated from the luminance measured in S620 or S640 in FIG. 17 and the reference value X determined according to the projection distance L acquired in S645. However, the present invention is not limited to this, and the correction amount used when generating the correction signal may be calculated without using the luminance ratio. For example, when the correction amount for correcting the brightness unevenness can be determined in advance according to the position of the pixel of the light modulation element 44 by the lens characteristics provided in the imaging optical system 45 (see FIG. 2), A correction signal may be generated based on the correction amount obtained using the reference correction amount and the projection distance L. According to this method, the correction amount can be appropriately determined according to the projection distance L between the projection apparatus 10 and the projection plane 50 without measuring the brightness that is an index of brightness. Therefore, it is possible to simplify the configuration of the apparatus necessary for the correction process and reduce the time required for the correction process.

  In S655 of FIG. 17, a linear relational expression is determined between the projection distance L and the reference value X and stored in advance in the ROM 231 or the EEPROM 233, and the reference value X corresponding to the projection distance L is obtained from the relational expression. However, the reference value X may be determined according to the projection distance L, and is not limited to the method of the second embodiment. Therefore, for example, it may be obtained from a lookup table without using a relational expression. In this case, the projection distance L in a predetermined range and the reference value X applied when the projection distance L is in the predetermined range May be stored in association with each other, and a reference value X corresponding to a range corresponding to the measured projection distance L may be obtained. Further, as a formula for obtaining the luminance correction amount, it may be obtained by directly substituting the projection distance L into a relational expression for determining the correction amount, such as C = X * L * (1-luminance ratio).

  In the second embodiment, as the projection distance L is longer, the pixel signal is corrected so as to increase the amount of increase due to correction of the white light component or the chromatic color component of the modulated light. You may make it correct a pixel signal so that the amount of reduction | decrease by correction | amendment of the light beam of the white component or chromatic component of modulated light may be enlarged, so that L is short. In this case, it is possible to perform correction in consideration of the color balance and the projection distance.

  Further, according to the projection distance L, the brightness priority mode and the color balance priority mode may be automatically switched in S220 of FIG. 10 according to the projection distance L detected by the distance detection unit 22. In this case, the predetermined value W is stored in advance in the ROM 231 or the EEPROM 233 so that the brightness priority mode is selected when the projection distance L is greater than or equal to the predetermined value W, and the color balance priority mode is selected when the projection distance L is less than the predetermined value W. The correction method stored in accordance with the projection distance L may be selected. With such a configuration, an appropriate correction method can be automatically selected according to the projection distance L, and the convenience for the user can be further improved.

2 is a left side view of the projection apparatus 10. FIG. 2 is a conceptual diagram showing a functional configuration of a projection apparatus 10. FIG. FIG. 5 is an explanatory diagram schematically showing a micromirror group 440 included in a light modulation element 44. 4 is an explanatory diagram schematically showing a state in which modulated light emitted from a micromirror group 440 passes through a projection lens 451 and is projected onto a screen 51. FIG. Calculation is based on the projection angle onto which the modulation angle emitted by the projection device 10 and the optical axis 70 of the imaging optical system 45 is projected and the modulation beam on which the pixel angle is 0 degrees is projected. 4 is a graph showing a relationship with a luminance ratio of a projected image on which modulated light at each pixel angle is projected. 12 is a timing chart for explaining a pixel signal after correction according to a specific example 1, a pixel signal after correction obtained by synthesizing the correction signal and the correction signal and the pixel signal before correction and the correction signal; FIG. 10 is an explanatory diagram for explaining various settings related to correction processing stored in an EEPROM 233 of the projection apparatus 10. It is a main flowchart which shows the flow of the main process of 1st Embodiment. FIG. 9 is a flowchart of a subroutine showing a flow of luminance measurement processing executed in the main processing shown in FIG. 8. FIG. 9 is a flowchart showing a flow of correction processing executed in the main processing shown in FIG. 8. FIG. 11 is a flowchart showing a flow of brightness priority processing executed in the correction processing shown in FIG. 10. FIG. FIG. 7 is a graph showing a relationship between a pixel angle and a luminance ratio of a projected image onto which modulated light at each pixel angle is projected according to the corrected pixel signal shown in FIG. 6. 12 is a timing chart for explaining a pixel signal after correction according to a specific example 2, a correction signal, and a pixel signal after correction obtained by combining the pixel signal before correction and the correction signal. 10 is a timing chart for explaining a pixel signal after correction according to a specific example 3, a pixel signal after correction obtained by synthesizing the correction signal and the pixel signal before correction and the correction signal. FIG. 15 is a graph showing a relationship between a pixel angle and a luminance ratio of a projected image on which modulated light at each pixel angle is projected in accordance with the corrected pixel signal shown in FIG. 14. It is a main flowchart which shows the flow of the main process of 2nd Embodiment. FIG. 17 is a subroutine flowchart showing a flow of luminance measurement processing executed in the main processing shown in FIG. 16. FIG.

DESCRIPTION OF SYMBOLS 10 Projector 21 Luminance measuring means 22 Distance detection means 25 Input means 34 Optical element drive part 41 Lamp control circuit 42 Lamp 44 Light modulation element 50 Projection surface 70 Optical axis 230 CPU
440 Micromirror group 441 Micromirror group 442 Micromirror group 443 Micromirror group 451 Projection lens

Claims (13)

A light source unit, a light modulation element that performs pulse width modulation on white and chromatic light emitted from the light source unit according to a pixel signal generated according to a pixel position based on an image signal, and the light modulation In a projection apparatus comprising a projection lens that magnifies and projects modulated light emitted from an element onto a projection surface,
Correction means for correcting a pulse width of a pixel signal generated according to a position of a pixel of the light modulation element based on the image signal, the position of the pixel of the light modulation element from an optical axis of the projection lens; Correction means for correcting the pixel signal corresponding to the pixel so as to increase the amount of increase due to correction of the light flux of the white component or the chromatic component of the modulated light ,
Determining means for referring to the image signal or the pixel signal to determine whether or not a light flux amount of the chromatic component of the modulated light is less than a predetermined value;
With
When the determination unit determines that the luminous flux amount of the chromatic component of the modulated light is less than a predetermined value, the correction unit determines that the chromatic color is more as the pixel position is farther from the optical axis of the projection lens. The pixel signal is corrected so as to increase the amount of increase due to the correction of the component luminous flux,
When it is determined by the determining means that the luminous flux amount of the chromatic component of the modulated light is greater than or equal to a predetermined value, the farther the pixel position is from the optical axis of the projection lens, the more the chromatic color component luminous flux is corrected. A projection apparatus characterized by not correcting the pixel signal for increasing the increase amount . A light source unit, a light modulation element that performs pulse width modulation on white and chromatic light emitted from the light source unit according to a pixel signal generated according to a pixel position based on an image signal, and the light modulation In a projection apparatus comprising a projection lens that magnifies and projects modulated light emitted from an element onto a projection surface,
Correction means for correcting a pulse width of a pixel signal generated according to a position of a pixel of the light modulation element based on the image signal, the position of the pixel of the light modulation element from an optical axis of the projection lens; Correction means for correcting the pixel signal corresponding to the pixel so as to increase the amount of increase due to correction of the light flux of the white component or the chromatic component of the modulated light ,
Determining means for referring to the image signal or the pixel signal to determine whether or not a light flux amount of the chromatic component of the modulated light is less than a predetermined value;
With
When the determination unit determines that the luminous flux amount of the chromatic component of the modulated light is greater than or equal to a predetermined value, the correction unit determines that the white component increases as the pixel position is farther from the optical axis of the projection lens. The pixel signal is corrected so as to increase the amount of increase due to the correction of the luminous flux of
When the light amount of the chromatic component of the modulated light is determined to be less than a predetermined value by the determining means, the distance from the optical axis of the projection lens increases as the white component light beam is corrected as the pixel position is farther from the optical axis of the projection lens. A projection apparatus characterized by not correcting the pixel signal for increasing the amount . The correction means is configured to increase the amount of decrease by correcting the luminous flux of the chromatic component of the modulated light as the pixel position of the light modulation element is closer to the optical axis of the projection lens. projection apparatus according to claim 1 or 2, characterized in the Turkey be corrected. A means for switching a correction method by the correction means, wherein the amount of increase due to the correction of the luminous flux of the white component or chromatic component of the modulated light is increased as the position of the pixel is farther from the optical axis of the projection lens. The brightness priority mode for correcting the pixel signal, and the amount of decrease due to correction of the light flux of the chromatic component of the modulated light as the pixel position is closer to the optical axis of the projection lens. The projection apparatus according to claim 3 , further comprising a mode switching unit that switches a color balance priority mode for correcting the signal. A projection distance acquisition means for acquiring a projection distance that is a distance from the projection device to a projection image projected on the projection plane;
5. The projection apparatus according to claim 4 , wherein the mode switching unit switches between the brightness priority mode and the color balance priority mode according to the projection distance acquired by the projection distance acquisition unit. A projection distance acquisition means for acquiring a projection distance that is a distance from the projection device to a projection image projected on the projection plane;
The correction unit corrects the pixel signal so that the amount of increase due to correction of a white component or a chromatic component of the modulated light is increased as the projection distance acquired by the projection distance acquisition unit is longer. projection apparatus according to any of claims 1 to 5, characterized. A projection distance acquisition means for acquiring a projection distance that is a distance from the projection device to a projection image projected on the projection plane;
The correction unit corrects the pixel signal so that the amount of decrease due to correction of the luminous flux of the chromatic component of the modulated light is increased as the projection distance acquired by the projection distance acquisition unit is shorter. projection apparatus according to any one of claims 3 to 5. Brightness acquisition means for acquiring a plurality of brightnesses of the projected image projected on the projection plane,
The correction unit increases the pixel signal so that the smaller the brightness acquired by the brightness acquisition unit is, the larger the increase amount due to correction of the white component or the chromatic component of the modulated light that projects the location is. projection apparatus according to any of claims 1 to 7, wherein the corrected. Projection apparatus according to any of claims 1 to 8, characterized in that it comprises a correction setting means for setting whether or not to correct the pixel signal by the correcting means. It said correction means generates a correction signal to be added to the pixel signal, by combining with the pixel signal and the correction signal, in any one of claims 1 to 9, characterized in that for correcting the pixel signal The projection device described. Projection apparatus according to any of claims 1 to 1 0, characterized in that performing the multi-color display by the field sequential method. The light modulation element, the projection apparatus according to any one of claims 1 to 1 1, characterized in that it consists of a digital micromirror device having a plurality of micro-mirrors. Wherein the correction means, according to the position of the micromirror, projection apparatus according to claim 1 2, wherein the correcting the pixel signal.

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