JP2008089929A - Video creating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video creating apparatus capable of creating a bright video using light emitted by a light source effectively while suppressing temperature rise of the light source. <P>SOLUTION: The video creating apparatus (projection apparatus 10) creates a color video of high brightness by temporal color mixing, and within one field video period, a light emitting signal output by a light emitting control means 30 includes a low brightness light emitting period Tc for making a 1st light source of primary colors emit light with low brightness, and a high brightness light emitting period Th for making a 2nd light source of primary colors emit light with high brightness, and a control signal output by a video control signal output means 32 controls a quantity of light emitted by the 1st light source in the low brightness light emitting period Tc, and also controls a quantity of light emitted by the 2nd light source in the high brightness light emitting period Th. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video generation apparatus that generates a color video by temporal color mixing, and more particularly to a video generation apparatus that generates a brighter video.

  2. Description of the Related Art Conventionally, a display system is known that relaxes restrictions on the response speed of a spatial light modulator and the transfer speed of a pulse width modulation signal (see, for example, Patent Document 1).

  The display system described in Patent Literature 1 includes a color variable filter unit that separates white light from a light source into a plurality of color component lights in a time-sharing manner, and a plurality of color component lights supplied from the color variable filter unit. A spatial light modulator that is illuminated and generates image light of each color component, and a brightness variable filter unit that switches the brightness of the light of the plurality of color components in three or more stages.

  Then, the luminance ratio of the variable brightness filter unit is selected to be an integer power of 2 such as 1: 4: 32, and the modulation time of the optical modulator is set to 3: 7: 7, so that the conventional modulation time of 255 is required. As a result, the modulation time of (3 + 7 + 7) = 17 can be achieved. Therefore, the time allotted for data transfer per pixel can be made longer than the conventional one, and as a result, the operation speed of the electric circuit can be reduced. Further, it is described that it contributes to reduction of power consumption, reduction of component cost, reduction of circuit design cost, and improvement of reliability, and a margin for circuit design can be obtained.

In addition, in a projection display device using a light-emitting diode as a light source, there is known an invention provided with a micromirror type switching device that selectively reflects light beams incident from different directions in a time division manner in order to improve the light utilization rate. (For example, refer to Patent Document 2).
JP 2003-209854 A (FIG. 3) Japanese Patent Application Laid-Open No. 2004-133312 (FIG. 1)

  In the display system disclosed in Patent Document 1, illumination light having a different luminance ratio is obtained by attenuating light emitted from a light source using a brightness variable filter unit, and thus light emitted from the light source is not effectively used. . Therefore, when a light emitting diode having a low light emission luminance is used as a light source, there is a problem that an image becomes dark.

  In addition, the projection display device described in Patent Document 2 has a problem that a reflection element such as a DMD is required in addition to the two-dimensional optical modulator. Further, the duty ratio allowed for the light emitting diode is about 1/10 when the light is emitted at the maximum rated current, and when the light emitting diode is used as the light source of the projection display device, the projected image tends to be dark. There is. Therefore, in the invention described in Patent Document 2, since the light emission period of the light source cannot be lengthened, there is a problem that a bright image cannot be provided.

  The present invention has been made to solve the above-described problem, and provides an image generation apparatus capable of generating a bright image by effectively using light emitted from a light source while suppressing temperature rise of each light source. The purpose is to do.

  In order to achieve the above object, the present invention divides one field of a video into sectors corresponding to different primary colors, and generates a light valve element for generating a video corresponding to the primary color during each sector, and each sector. A first light source that irradiates the light valve element with low-luminance light of the primary color during the period of time, a second light source that irradiates the light valve element with high-luminance light of the primary color during the period of each sector, A light emission control means for outputting a light emission signal for controlling the amount of light emitted from the light source, and a video control signal output means for inputting a video signal and outputting a control signal to the light valve element. An image generation apparatus for generating an image, wherein the light emission signal output from the light emission control means includes a low luminance emission period in which the first light source emits light and a high luminance in which the second light source emits light within the period of the one field. Departure The control signal output from the video control signal output means controls the amount of light emitted from the light source during the low luminance emission period and the amount of light emitted from the light source during the high luminance emission period. It is characterized by doing.

  Further, in the invention according to claim 2, the light emission control means has the same pulse width as the sector period which is each light emission period of the RGB light when the RGB light from the first light source is irradiated in a time division manner. One light source is driven, and the second light source is driven with a pulse width shorter than the sector period.

  Further, the invention according to claim 3 is characterized in that the light emission control means drives the first light source at a continuous rated current or less and drives the second light source at a current larger than the continuous rated current.

  The invention according to claim 4 is characterized in that the first light source and the second light source are constituted by light-emitting diodes that are pulse-driven.

  The invention according to claim 5 is characterized in that the first light source and the second light source are constituted by a laser light emitting element driven by pulses.

  The invention described in claim 6 is characterized in that a light emitting diode is used as the first light source and a laser diode is used as the second light source.

  According to a seventh aspect of the present invention, the light emission control unit controls the low-luminance emission period in which the primary color light source emits light at low luminance and the high-luminance emission period in which the primary color emits light at high luminance. It is characterized by performing.

  The invention described in claim 8 is characterized in that a light source of three primary colors of red, green and blue is used as the second light source.

  In the invention according to claim 9, the light emission control means inputs the video signal, extracts the maximum luminance in one or a plurality of fields of the video, and projects the light with the extracted maximum luminance. Control to emit the primary color is performed.

  According to a tenth aspect of the present invention, the light emission control means controls the light emission time of the light source in the high luminance light emission period when controlling the amount of light for projecting the maximum luminance in one field of the image. Features.

  In the invention according to claim 11, the light emission control means controls the current supplied to the light source during the high luminance light emission period when controlling the amount of light for projecting the maximum luminance in one field of the image. It is characterized by doing.

  According to a twelfth aspect of the present invention, the second light source of the second primary color is emitted after the first low-luminance light emission period in which the light emission control means causes the first light source of the first primary color to emit light with low luminance. A second high-luminance light emission period for emitting light with high luminance is provided, and then a control for providing a third low-luminance light emission period for causing the first light source of the third primary color to emit light with low luminance is performed.

  According to a thirteenth aspect of the present invention, the light emission control means sequentially emits the first light source of each primary color at a low luminance to generate one field of an image, and then sets the second light source of each primary color at a high luminance. It is characterized by performing control to sequentially emit light.

  Further, in the invention described in claim 14, the light emission control means causes the second light source of the primary color to emit light with high luminance immediately after the low luminance light emission period in which the first light source of the predetermined primary color emits light with low luminance. Control for providing a high-luminance light emission period is performed.

  Further, in the invention described in claim 15, the light emission control means causes the primary light source of the primary color to emit light with low brightness immediately after the high brightness light emission period in which the secondary light source of the predetermined primary color emits light with high brightness. Control is provided to provide a low-luminance light emission period.

  Further, in the invention described in claim 16, the video generation signal output means outputs a video control signal for generating a video using light of both low luminance and high luminance to the light valve element. The gradation of the image for each pixel is adjusted.

  According to a seventeenth aspect of the present invention, there is provided a light valve element that divides one field of a video into sectors corresponding to different primary colors, and generates a video corresponding to the primary color during each sector, and each sector. A light source that irradiates the light valve element with light of a plurality of types of brightness of the primary color, a light emission control means that outputs a light emission signal for controlling the light emission amount of the light source, and a video signal that is input to the light Video control signal output means for outputting a control signal to the valve element, a video generation apparatus for generating a color video by time mixing of primary colors of a plurality of types of luminance, the light emission signal output by the light emission control means, Within the period of the one field, the control signal output from the video control signal output means has a signal for causing the primary color light source to emit light with a plurality of different luminances. There the light source is characterized by controlling the amount of light emission.

  The invention according to claim 18 is provided with a pulse driving unit that controls the light emission control means to emit light at a plurality of types of brightness by controlling a current supplied to the light source. It is characterized by.

  According to a nineteenth aspect of the present invention, there is provided a light valve element that divides one field of an image into sectors corresponding to different primary colors, and generates an image corresponding to the primary color during each sector, and each sector. A light source for irradiating the light valve element with the primary color light, a white light source for irradiating the light valve element with white light, and a light emission control means for outputting a light emission signal for controlling the light emission amount of the light source And a video control signal output means for inputting a video signal and outputting a control signal to the light valve element, generating a color video by temporal color mixing and generating a high brightness video by adding white light The light emission signal output from the light emission control means includes a primary color light emission period in which the primary color light source emits light and a white light source in which the white light source emits light within the period of the one field. The control signal output from the video control signal output means controls a video generated by the light valve element during the primary color light emission period and is generated by the light valve element during the white light emission period. It is characterized by controlling video.

  According to a twentieth aspect of the invention, a plurality of primary color light sources are used as the white light source, and white light is generated by simultaneously emitting light from the plurality of primary color light sources.

  Further, in the invention according to claim 21, the light emission control means performs control to cause the white light source to emit light after sequentially emitting light of all primary colors in one field of the video in time division. It is characterized by.

  According to a twenty-second aspect of the present invention, after the light emission control means causes all primary color light sources to sequentially emit light in one field of an image after time division, all the primary color light sources and the white light source. Is controlled to emit light.

  According to a twenty-third aspect of the present invention, the light emission control unit provides a white light emission period for causing the white light source to emit light after the first primary color light emission period for causing the first primary color light source to emit light. Control for providing a second primary color light emission period for emitting light of the two primary colors is performed.

  The invention according to claim 24 is characterized in that the light emission control means performs control of emitting light of a white light source after sequentially generating light of each primary color to generate one field of an image.

  Further, in the invention described in claim 25, the light emission control means inputs the video signal, extracts the maximum luminance in one or a plurality of fields of the video, and projects the light with the extracted maximum luminance. The white light source is controlled to emit light.

  According to a twenty-sixth aspect of the present invention, the light emission control means controls the light emission time of the white light source during the white light emission period when controlling the amount of light for projecting the maximum luminance in one field of the image. It is characterized by.

  The invention according to claim 27 is characterized in that the light emission control means controls the current supplied to the white light source when controlling the amount of light for projecting the maximum luminance in one field of an image. To do.

  The invention according to claim 28 is characterized in that the light emission control means performs control to overlap a primary color light emission period in which the primary color light source emits light and a white light emission period in which the white light source emits light. To do.

  The invention according to claim 29 or claim 34 is characterized in that DMD is used for the light valve element.

  The invention according to claim 30 is independent of a first light source that emits the primary color with low luminance during the low luminance emission period and a second light source that emits the primary color with high luminance during the high luminance emission period. The light valve element illuminates the light valve element with light emitted from the first light source and light emitted from the second light source at different angles.

  The invention according to claim 31 is characterized in that the light valve element illuminates the light emitted from the first light source and the light emitted from the second light source at symmetrical angles.

  The invention described in claim 32 is characterized in that a light emitting diode is used for the primary color light source or the white light source.

  The invention according to claim 33 is characterized in that a laser diode is used for the primary color light source or the white light source.

  The invention as set forth in claim 35 is characterized in that a transmissive or reflective liquid crystal display element is used as the light valve element.

  The invention according to claim 36 is characterized in that a polarization conversion element or a polarization beam splitter is provided between the light source and the light valve element.

  According to the first aspect of the present invention, within one field period, a low-luminance light emission period in which the primary light source of the primary color emits light with low brightness, and a high-luminance light emission period in which the secondary light source of the primary color emits light with high brightness. Provided, the amount of light emitted from the first light source during the low-luminance light emission period is controlled and the amount of light emitted from the second light source during the high-luminance light emission period is controlled. The lighting time of the light source in one field can be lengthened. Therefore, it is possible to suppress an increase in the temperature of each light source and increase the amount of video light. In addition, the gradation range of the video can be widened and the contrast of the video can be increased.

  According to the second aspect of the invention, the light emission control means has a pulse width substantially the same as the sector period that is each light emission period of the RGB light when the RGB light from the first light source is irradiated in a time division manner. Thus, since the first light source is driven and the second light source is driven with a pulse width shorter than the sector period, it is possible to suppress the temperature rise of each light source and to increase the light quantity of the image.

  According to the invention described in claim 3, the light emission control means drives the first light source at the continuous rated current or less and drives the second light source at a current larger than the continuous rated current for a short period of time. Therefore, it is possible to suppress the temperature rise of the second light source and increase the amount of video light.

  According to the invention described in claim 4, since the first light source and the second light source are composed of light-emitting diodes that are pulse-driven, it is possible to provide a video generation device that is small and consumes less power. .

  According to the fifth aspect of the present invention, since the first light source and the second light source are configured by pulse-driven laser light emitting elements, it is possible to provide a small-sized and low power consumption image generating device. Become.

  Further, according to the invention described in claim 6, since a light emitting diode is used as the first light source and a laser diode is used as the second light source, an image generating apparatus having a relatively bright image and low power consumption is provided. Is possible.

  According to the invention described in claim 7, the light emission control means performs control to overlap the low-luminance emission period in which the primary color light source emits light with low luminance and the high-intensity emission period in which the primary color emits light with high luminance. Since this is done, the gradation range of the video can be widened and the contrast of the video can be increased.

  According to the invention described in claim 8, since the light sources of the three primary colors of red, green, and blue are used as the second light source, it is possible to increase the light amount of the color image and obtain a bright image.

  According to the invention of claim 9, the light emission control means inputs the video signal, extracts the maximum luminance in one or a plurality of fields of the video, and is a light amount for projecting at the extracted maximum luminance, Since the control for emitting the primary colors is performed, unnecessary light emission can be prevented and the temperature of the light source can be prevented from rising.

  According to the invention described in claim 10, the light emission control means controls the light emission time of the light source in the high luminance light emission period when controlling the light amount for projecting the maximum luminance in one field of the image. Therefore, unnecessary light emission can be prohibited to prevent the temperature of the light source from rising.

  According to the invention described in claim 11, the light emission control means controls the current supplied to the light source during the high luminance light emission period when controlling the amount of light for projecting the maximum luminance in one field of the image. Since it did in this way, unnecessary light emission can be prohibited and the temperature rise of a light source can be prevented.

  According to the invention described in claim 12, the light emission control means has the second primary light source of the second primary color after the first low luminance light emission period for causing the first light source of the first primary color to emit light with low luminance. Since the second high-luminance light emission period for emitting light with high luminance is provided, and then the third low-luminance light emission period for causing the first light source of the third primary color to emit light with low luminance is performed. It is possible to lengthen the lighting time of the light source in one field of the image while ensuring the heat radiation time. Therefore, it is possible to provide a bright image while suppressing the temperature rise of each light source.

  According to the invention described in claim 13, the light emission control means sequentially emits the first light source of each primary color with low luminance to generate one field of the image, and then sets the second light source of each primary color to the high luminance. Since the control for sequentially emitting light is performed, each light source can emit light intermittently. Therefore, it is possible to lengthen the lighting time of the light source in one field of the image while ensuring the heat radiation time of the light source.

  According to the invention described in claim 14, the light emission control means causes the second light source of the primary color to emit light with high luminance immediately after the low luminance light emission period in which the first light source of the predetermined primary color emits light with low luminance. Since the control for providing the high luminance light emission period is performed, the light valve element can be driven efficiently. Accordingly, the frame rate of the video can be improved. In addition, the temperature rise of the primary color light source can be suppressed, and the amount of light emitted by the light source within one field of the image can be increased.

  According to the invention described in claim 15, the light emission control means causes the primary light source of the primary color to emit light with low brightness immediately after the high brightness light emission period for causing the second light source of the predetermined primary color to emit light with high brightness. Since the control for providing the low luminance light emission period is performed, the light valve element can be driven efficiently. Accordingly, the frame rate of the video can be improved.

  According to the invention described in claim 16, the video generation signal output means outputs each video control signal for generating a video using both low-luminance and high-luminance light to the light valve element. Since the gradation of the image for each pixel is adjusted, the generation time of one image field can be shortened, and the frame rate of the image can be improved. In addition, the gradation range of the video can be widened and the contrast of the video can be increased.

  According to the seventeenth aspect of the present invention, the light emission signal output from the light emission control means is provided with a signal for causing the primary color light source to emit light at a plurality of different brightness levels, and the control signal output from the video control signal output means is Since the light quantity emitted from the light source is controlled at a plurality of different brightness levels, it is possible to generate an image by adding the image at the time of low brightness light emission and the image at the time of light emission at a high brightness. Therefore, it is possible to shorten the generation time of the video 1 field and improve the video frame rate. Further, by generating a video by controlling the light valve element in each of the light emission period with low luminance, the light emission period with medium luminance, and the light emission period with high luminance, it is possible to improve the frame rate of the video. In addition, the gradation range of the video can be widened and the contrast of the video can be increased.

  Further, according to the invention described in claim 18, since the pulse drive unit for controlling the light source to emit light with a plurality of types of luminance is controlled by controlling the current supplied to the light source, the low luminance is easily achieved. It is possible to control the amount of light emitted with medium or high luminance.

  According to the nineteenth aspect of the present invention, the light emission signal output from the light emission control means is provided with a primary color light emission period in which the primary color light source emits light and a white light emission period in which the white light source emits light. Since the control signal output from the output means controls the image generated by the light valve element in the primary color light emission period and also controls the image generated by the light valve element in the white light emission period, a plurality of types of primary colors can be controlled. It is possible to generate one field of the image by emitting the light source and supplementing the light amount of the image by separately emitting white light. Therefore, it is possible to increase the light amount of the video generated by the video generation device while suppressing the temperature rise of each light source. Therefore, even when the distance to the projected image is long, it is possible to prevent a problem that the image becomes dark.

  According to the invention of claim 20, since a plurality of primary color light sources are used as a white light source and white light is generated by simultaneously emitting the plurality of primary color light sources, The amount of light can be increased, and a bright image can be provided.

  According to the invention as set forth in claim 21, the light emission control means performs control to cause all the primary color light sources to emit light in a time-division manner in one field of an image and then to emit a white light source. Therefore, each light source can emit light intermittently. Accordingly, it is possible to provide a bright image by securing the time for heat radiation of the light source and extending the lighting time of the light source in one field of the image.

  According to the invention described in claim 22, after the light emission control means causes all the primary color light sources to emit light sequentially in one field of the image in a time-division manner, all the primary color light sources and the white light source are turned on. Since the emission control is performed, a bright image can be generated.

  According to the invention of claim 23, the light emission control means provides a white light emission period for causing the white light source to emit light after the first primary color light emission period for causing the first primary color light source to emit light, and thereafter Since the control for providing the second primary color light emission period for emitting the light source of the second primary color is performed, it is possible to intermittently perform the low-luminance light emission of the plurality of primary colors and the white light emission. It is possible to secure the time for heat dissipation and lengthen the lighting time of the light source in one field of the image. Therefore, a bright image can be provided while suppressing the temperature rise of each light source.

  According to the invention of claim 24, since the light emission control means sequentially controls the light emission of the white light source after generating the light source of each primary color to generate one field of the image. Each light source can emit light intermittently. Therefore, it is possible to lengthen the lighting time of the light source in one field of the image while ensuring the heat radiation time of the light source.

  According to the invention of claim 25, the light emission control means inputs the video signal, extracts the maximum luminance in one or a plurality of fields of the video, and emits white light with a light amount for projecting at the extracted maximum luminance. Since the light source is controlled to emit light, unnecessary light emission can be prevented and temperature rise of the light source can be prevented.

  According to the invention described in claim 26, the light emission control means controls the light emission time of the white light source during the white light emission period when controlling the light amount for projecting the maximum luminance in one field of the image. Therefore, unnecessary light emission can be prohibited to prevent the temperature of the light source from rising.

  According to the invention of claim 27, the light emission control means controls the current supplied to the white light source when controlling the amount of light for projecting the maximum luminance in one field of the image. The useless heat generation of the light source can be prevented, and the temperature rise of the light source can be suppressed.

  According to the invention of claim 28, the light emission control means performs control to overlap the primary color light emission period for emitting the primary color light source and the white light emission period for emitting the white light source. Gradation can be displayed in a short time, and the frame rate of the video can be improved while maintaining the light quantity of the video generated by the video generation device.

  According to the invention of claim 29 or claim 34, since the DMD is used for the light valve element, it is possible to efficiently modulate the light emitted from the light source and generate a brighter image. In addition, the high responsiveness of the micromirror device makes it possible to improve the video frame rate.

  According to the invention of claim 30, the first light source that emits the primary color with low luminance during the low luminance emission period and the second light source that emits the primary color with high luminance during the high luminance emission period are independently provided. Since the light valve element illuminates the light emitted from the first light source and the light emitted from the second light source at different angles, the first light source and the second light source can be provided at different locations. It becomes possible. Therefore, the cooling property of the light source can be improved, and the degree of freedom regarding the arrangement of the light source can be increased.

  According to the invention described in claim 31, since the light valve element illuminates the light emitted from the first light source and the light emitted from the second light source at symmetric angles, both of the DMDs The locking position can be used to generate a video. Therefore, DMD can be used efficiently.

  According to the invention of claim 32, since the light emitting diode is used as the primary color light source or the white light source, it is possible to provide a small-sized and low power consumption image generating device.

  According to the invention of claim 33, since the laser diode is used as the primary color light source or the white light source, it is possible to provide a small-sized and low power consumption image generating device.

  According to the thirty-fifth aspect of the present invention, since a transmissive or reflective liquid crystal display element is used as the light valve element, an image with high color tone and gradation reproducibility can be generated.

  According to the invention of claim 36, since the polarization conversion element or the polarization beam splitter is provided between the light source and the light valve element, the image generation apparatus using the liquid crystal display panel is configured with a small number of components. can do.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an internal configuration of a projection apparatus according to one embodiment of the video generation apparatus according to the present invention.

  The projection apparatus according to the present embodiment is an apparatus that projects light onto a projection surface (screen) so that a light valve element generates an image using light emitted from a light source and can be observed by an observer.

  A projection apparatus 10 shown in FIG. 1 condenses diffuse light emitted from each of the light sources 12 and a plurality of color light sources 12 whose light emission periods can be controlled independently, and provides more uniform illumination light as a light valve. A condenser lens 14 that irradiates the element 20, a dichroic mirror 16 that synthesizes light of a plurality of wavelengths by transmitting light of a predetermined wavelength and reflecting light of a specific wavelength, and each pixel are provided. A light valve element 20 that generates light by causing light to enter the projection lens group 24 using a oscillating mirror 22 and a projection lens group 24 that projects an image generated by the light valve element 20 onto a screen 26 are provided. ing.

  In addition, the projection apparatus 10 includes a light emission control means 30 that outputs a light emission signal for sequentially emitting light of a plurality of types of primary colors in a time-division manner, and a mirror 22 of the light valve element 20 by inputting a video signal. The video control signal output means 32 for outputting a control signal for controlling the swing, the input means 170 including a switch, a cursor button, etc. for inputting various information by the user, and the whole projection apparatus 10 are controlled. And an information processing means 180.

  In addition, the projection apparatus 10 includes a RAM 181 that is used as a work area when the information processing unit 180 executes processing, a ROM 183 that records various types of information such as processing programs executed by the information processing unit 180 and constants, and clocking time. Means 190, an angle-of-view detection means 191 for detecting the angle of view of the image projected by the projection lens group 24, and a projection angle acquisition means 192 for obtaining the vertical angle of the image projected by the projection apparatus 10. .

  Information processing means 180, light emission control means 30, video control signal output means 32, input means 170, RAM 181, ROM 183, timing means 190, angle of view detection means 191, projection angle acquisition means 192, etc. in the projection apparatus 10 The peripheral circuits are connected by a bus 199, and each peripheral circuit can be controlled based on a processing program executed by the information processing means 180. Note that the processing program executed by the information processing means 180 can be provided by a recording medium or communication. Each peripheral circuit can also be constituted by an ASIC or the like.

  The light emission control means 30 time-divides the primary color light source 12 within a period of one field of the image and sequentially emits light at a low luminance, and sequentially emits the primary color light source 12 at a high luminance and sequentially emits light. A light emission signal having a high luminance light emission period is output to the light source 12.

  The video control signal output means 32 emits the light quantity for each pixel based on the video signal during the low luminance light emission period in which the light source 12 emits the primary color with low luminance and the high luminance light emission period in which the light source 12 emits light with high luminance. A function of outputting a video generation signal for controlling the light to the light valve element 20 is provided. For example, as shown in FIG. 1, when only the pixel of the mirror 22 </ b> B is set to an off state in one video field, so-called off light does not enter the projection lens group 24. Accordingly, the image 27 projected on the screen 26 is darkened only in the pixel image portion of the mirror 22B, and an image can be generated. Note that the gradation of the video is expressed using time mixing by controlling the time during which the mirror 22 is turned on.

  The video control signal output means 32 outputs a light amount correction signal to the light valve element 20 in both the low-luminance light emission period and the high-luminance light emission period. The lighting time of the light source in one field can be lengthened. Therefore, it is possible to increase the light quantity of the video generated by the video generation device while suppressing the temperature rise of each light source. In addition, by temporally mixing the video generated during the low luminance light emission period and the video generated during the high luminance light emission period, gradation display can be performed in a short sector time, and the frame rate can be improved.

  FIG. 2 is a time chart showing the timing of the video generation signals Tr, Tg, Tb in the low luminance light emission period Tc and the timing of the light amount correction signals Hr, Hg, Hb in the high luminance light emission period Th.

  In the embodiment shown in FIG. 2, one field of video is divided into an R sector that generates a red video, a G sector that generates a green video, and a B sector that generates a blue video. The timing of a so-called field-sequential method, in which a color image is generated by time-mixing each image, is shown.

  In the embodiment shown in FIG. 2, each sector has the same light source as the low-luminance light emission period Tc in which the primary color light sources 12 of R, G, and B are sequentially emitted at a low luminance so as not to overlap each other. A high-luminance light emission period Th for emitting light 12 with high luminance is provided. In the embodiment shown in FIG. 2, the luminance of the high luminance light emitting period Th that emits light with high luminance is expressed higher than the block that emits light during the low luminance light emitting period Tc. The difference is expressed.

  As shown in FIG. 2, the light source 12 is driven in the low luminance emission period Tc having the same pulse width as the sector period, and the light source 12 is driven in the high luminance emission period Th having a pulse width shorter than the sector period. Yes. The current value supplied to the light source 12 during the low-luminance light emission period Tc is equal to or less than each current of the continuous bank. In addition, the current value supplied to the light source 12 during the high luminance light emission period Th is set to pulse driving that is equal to or greater than each current value of the continuous bank.

  For a pixel that generates an image with a small amount of red component, the image control signal output unit 32 outputs an image generation signal for generating a fine red tone Tr1 in the low luminance emission period Tc of the R sector. During this period, the light is output to the light valve element 20. For example, for a pixel that generates an image with a small amount of green component, an image generation signal for generating a fine green gradation is output during the period of Tg1 in the low luminance emission period Tc of the G sector. Output to. Further, for example, for a pixel that generates an image with a small amount of blue component, an image generation signal for generating a fine gradation of blue in the low luminance light emission period Tc of the B sector is a light valve element 20 during the period Tb1. Output to.

  Further, the video control signal output means 32 generates a video generation signal for generating a fine gradation of red in the low-luminance light emission period Tc of the R sector, for a pixel that generates a video with a red component having medium brightness. Is output to the light valve element 20 during the period Hr2 during the Tr2 period. Similarly, a video generation signal is output to the light valve element 20 during the Tg2 and Hg2 periods in the low luminance light emission period Tc of the G sector, and the light valve element 20 is output during the Tb2 and Hb2 periods in the low luminance light emission period Tc of the B sector. The video generation signal is output.

  Also, the video control signal output means 32 generates a video generation signal for generating a fine gradation of red in the low-luminance light emission period Tc of the R sector, for pixels that generate a video containing a lot of red components. Is output to the light valve element 20 during the period Hr3 during the Tr3 period. Similarly, a video generation signal is output to the light valve element 20 during the Tg3 and Hg3 periods in the low-luminance light emission period Tc of the G sector, and is supplied to the light valve element 20 during the Tb3 and Hb3 periods in the low-luminance light emission period Tc of the B sector. Output video generation signal.

  In this way, by using both the low-luminance light emission period Tc and the high-luminance light emission period Th to express a fine gradation and a rough gradation with time mixing, the gradation of the image is expanded and the contrast of the image is improved. And bright images can be provided. Further, the frame rate can be improved by performing gradation display in a short sector time.

  In the embodiment shown in FIG. 2, the light emission control unit 30 emits the primary color light source 12 with high luminance immediately after the low luminance light emission period Tc when the predetermined primary color light source 12 emits light with low luminance. Control for providing the period Th is performed. By controlling the light emission of the light source 12 in this way, it is possible to emit light with relatively high luminance immediately after the low luminance light emission period Tc when the light source 12 is at a relatively low temperature, thereby increasing the amount of emitted light. . In addition, immediately after generating an image using a predetermined primary color, the light valve element 20 can be efficiently driven by causing the light source of the primary color to emit light with high luminance, thereby improving the frame rate of the image. Can do.

  Further, as shown in FIG. 2, in addition to causing the primary color light source 12 to emit light with high luminance immediately after the low luminance light emission period Tc, control for providing the low luminance light emission period Tc immediately after the high luminance light emission period Th is performed. May be. As described above, the light valve element 20 can be driven efficiently and the frame rate of the video can be improved by continuing the high luminance light emission period Th and the low luminance light emission period Tc.

  In controlling the amount of light for projecting the maximum luminance in one field of the image, the light emission control means 30 may be configured to control the light emission time of the light source 12 in the high luminance light emission period Th. You may comprise so that the electric current supplied to may be controlled. Further, the light emission amount of the light source 12 may be controlled by controlling both the high luminance light emission period Th and the current. By configuring in this way, unnecessary light emission of the light source 12 can be prohibited and temperature rise of the light source 12 can be suppressed.

  FIG. 3 shows a time chart in which the luminance of one or a plurality of fields of an image is acquired, and the light source 12 is controlled to emit light during the high luminance light emission period Th with the light emission amount corresponding to the luminance.

  In the embodiment shown in FIG. 3, in order to obtain the light emission amount according to the luminance of one or more fields of the video, the light emission control means 30 shortens the high luminance light emission period Th according to the luminance of one or more fields of the video. The state of the control to change to the pulse is shown.

  Next, another embodiment of the timing of the low luminance light emission period Tc and the high luminance light emission period Th of each primary color will be described with reference to FIG.

  FIG. 4 shows a second example in which the blue (second primary color) light source 12 emits light with high luminance after the first low luminance light emission period Tc in which the red (first primary color) light source 12 emits light with low luminance. It is a time chart which shows embodiment which provided the 3rd low-intensity light emission period Tc which provided the high-intensity light emission period Th, and after that the green (3rd primary color) light source 12 light-emitted with low brightness.

  In the embodiment shown in FIG. 2, the red (first primary color) light source 12 emits light with high luminance after the low luminance light emission period Tc in which the red (first primary color) light source 12 emits light with low luminance. A time chart is shown in which a high-intensity light emission period Th is provided, followed by a low-intensity light emission period Tc in which the green (third primary color) light source 12 emits light at low intensity.

  In the embodiment shown in FIG. 4, a period for cooling the light source 12 is provided by increasing the interval between the low luminance emission period Tc and the high luminance emission period Th for each primary color, while preventing the temperature of the light source 12 from rising. The amount of emitted light is increased. Therefore, according to the embodiment shown in FIG. 4, it is possible to generate a bright image while ensuring the time for heat radiation of the light source.

  Next, another embodiment of the timing of the low luminance light emission period Tc and the high luminance light emission period Th of each primary color will be described with reference to FIG.

  In the embodiment shown in FIG. 2, the red high luminance light emission period Th is provided after the red low luminance light emission period Tc, and then the green low luminance light emission period Tc and the green high luminance light emission period Th are provided. Further, a time chart in which a blue low-luminance light emission period Tc and a blue high-luminance light emission period Th are provided is shown.

  In the embodiment shown in FIG. 5, after the red, green, and blue primary color light sources 12 are sequentially emitted at low luminance to generate one field of an image, the red, green, and blue primary color light sources 12 are increased. Control is performed to emit light sequentially with luminance. In this way, after generating an image using a plurality of primary colors, each light source 12 can emit light intermittently by causing the light sources 12 of each primary color to emit light with high luminance. Therefore, it is possible to lengthen the lighting time of the light source in one field of the image while securing the heat radiation time of the light source 12.

  In the embodiments shown in FIGS. 3, 4 and 5, the current value supplied to the light source 12 during the low-luminance light emission period Tc is set to be equal to or less than each current of the continuous bank. In addition, the current value supplied to the light source 12 during the high luminance light emission period Th is set to pulse driving that is equal to or greater than each current value of the continuous bank.

  Next, an embodiment in which a medium luminance emission period Tm is provided in addition to the low luminance emission period Tc and the high luminance emission period Th of each primary color will be described with reference to FIG.

  In FIG. 2 described above, an embodiment in which gradation display of an image is performed using two types of luminance, that is, a low luminance light emission period Tc and a high luminance light emission period Th is shown, but FIG. 6 illustrates a low luminance light emission period Tc. 5 is a time chart showing an embodiment in which a medium luminance emission period Tm is provided in addition to the high luminance emission period Th and gradation display is performed using three types of luminance.

  As shown in FIG. 6, the light emission control means 30 outputs a light emission signal that causes the primary color light source 12 to emit light with three different luminances within a period of one field. The video control signal output means 32 outputs a control signal for controlling the amount of light emitted from the light source 12 at three different brightness levels. Thus, the light valve element 20 is controlled to generate an image in each of the low-luminance light emission period Tc, the medium-luminance light emission period Tm, and the high-luminance light emission period Th. Therefore, the gradation of the video can be further increased, and the generation time of the video 1 field can be further shortened. In the embodiment shown in FIG. 6, the embodiment in which the light source 12 emits light with three types of luminance, that is, the low luminance light emission period Tc, the medium luminance light emission period Tm, and the high luminance light emission period Th is shown. The display is not limited to three types of luminance, and gradation display can be performed by combining four or more types of luminance.

  Further, in order to cause the light source 12 to emit light with the plurality of types of luminance, a pulse driving unit that controls the light source 12 to emit light with the plurality of types of luminance by controlling the current supplied to the light source 12 is used as the light emission control unit. 30.

  By controlling the current supplied to the light source 12 or the light emission time, it is possible to easily emit light with a low luminance, a medium luminance, or a high luminance. Further, the correction of the emitted light quantity is performed by previously storing a luminance light quantity table in which the relationship between the luminance of one or a plurality of fields of an image or an average value thereof and the emitted light quantity of each light source 12 to be controlled is stored in the ROM 183 or the like. The light emission control unit 30 may be configured to obtain a light emission amount by referring to a luminance light amount table and perform control to emit a plurality of primary colors simultaneously.

  Next, FIG. 7 shows a time chart showing another embodiment in which gradation display is performed by providing a low luminance light emission period Tc, a medium luminance light emission period Tm, and a high luminance light emission period Th.

  In FIG. 6 described above, the embodiment in which the medium luminance light emitting period Tm is provided immediately after the low luminance light emitting period Tc and the high luminance light emitting period Th is provided immediately after that is shown. However, as shown in FIG. The order of the light emission periods can be changed. In the embodiment shown in FIG. 7, a medium luminance light emission period Tm is provided at the beginning of one field, a low luminance light emission period Tc with a relatively small amount of heat generation is provided thereafter, and a high luminance light emission period Th is provided thereafter, and the image level is increased. The key is displayed.

  By configuring the projection device 10 in this way, it is possible to generate a bright image while suppressing the temperature rise of the light source 12 to some extent.

  In the embodiment shown in FIGS. 6 and 7, the current value supplied to the light source 12 during the low luminance light emission period Tc is set to be equal to or less than each current of the continuous bank. In addition, the current value supplied to the light source 12 during the medium luminance light emission period Tm and the high luminance light emission period Th is set to pulse drive that is equal to or greater than each continuous bank current value.

  Next, an embodiment in which a first light source that emits light with low brightness during the low brightness light emission period Tc and a second light source that emits light with high brightness during the high brightness light emission period Th will be described with reference to FIG. .

  FIG. 8 is a diagram showing an embodiment of a projection apparatus 110 that includes two independent light emitting sources in one light source 12A. Note that components having the same functions as those of the projection apparatus 10 shown in FIG. 1 are denoted by the same reference numerals, and description of the functions is omitted.

  A light source 12A for each color of R, G, and B shown in FIG. 8 includes two light emitting sources capable of emitting light independently in one light emitting element. Of these two light sources, one is used as a low-luminance first light source, and the other is used as a high-luminance second light source.

  As shown in FIG. 8, an independent first light source (low-intensity light source) and second light source (high-intensity light source) are arranged adjacent to each other in the vicinity of the optical axis of the condenser lens 14 to provide a first light source in the light source 12A. Is made to emit light during the low-luminance light emission period Tc and the second light source in the light source 12A emits light during the high-luminance light emission period Th, thereby forming a compact and high-luminance illumination system 11. Therefore, a bright image can be generated while suppressing the temperature rise of the individual light sources of the first light source and the second light source. In addition, as shown in FIG. 8, when the independent first light source and second light source are provided in one light source 12A, the light emission control means 30 has a low luminance light emission period Tc and a high luminance light emission period. Control may be performed by providing a timing for overlapping Th.

  Next, another embodiment including a first light source that emits light with low brightness during the low brightness light emission period Tc and a second light source that emits light with high brightness during the high brightness light emission period Th will be described with reference to FIG. explain.

  FIG. 9 shows a video control signal output while the light source 12 emits the primary color in the low-luminance light emission period Tc in the projection apparatus 210 including the plurality of primary color light sources 12 and the plurality of primary color light sources 12B. It is a figure which shows the state which the means 32 outputs a control signal with respect to the light valve element 20, and is producing | generating the image | video.

  Also, FIG. 10 shows that the video control signal output means 32 controls the light valve element 20 while the light source 12B emits the primary color in the high luminance light emission period Th in the projection device 210 shown in FIG. It is a figure which shows the state which has output the signal and produced | generated the image | video.

  In the embodiment shown in FIG. 9 and FIG. 10, a device such as a DMD provided with an oscillating reflector having a first locking point and a second locking point for each pixel is used as the light valve element 20. When the reflection plate of the pixel is locked at the first locking point, the light emitted from the light source 12 during the low luminance light emission period Tc is incident on the projection lens group 24 to project the image light. It is configured. When the reflection plate of the pixel is locked at the second locking point, the light source 12B causes the light emitted during the high luminance light emission period Th to enter the projection lens group 24 and project the image light. The image brightness is corrected.

  When a DMD is used as the light valve element 20 and the reflection plate of the DMD pixel has a locking point of ± θ symmetrical to the center of oscillation, the light emitted from the light source 12 and the light source 12B Can be configured to illuminate the light valve element 20 at different angles. In the embodiment shown in FIGS. 9 and 10, the light valve element 20 is illuminated at an angle at which the light emitted from the light source 12 and the light emitted from the light source 12B are symmetrical with respect to the optical axis incident on the projection lens group 24. It is configured to do.

  As described above, by arranging the light source 12 and the light source 12B at different locations, it is easy to thermally insulate the light source 12 and the light source 12B, and a bright image can be provided by suppressing a temperature rise of the light source. It becomes possible. In addition, as each said light source 12, 12B, a high-intensity light emitting diode or a laser diode can be used. Alternatively, a light emitting diode can be used as the low-luminance first light source, and a laser diode can be used as the high-luminance second light source.

  Next, an embodiment of control signal generation processing of the light valve element 20 executed by the video control signal output means 32 of the projection apparatus will be described with reference to FIG.

  As shown in FIG. 11, when the video control signal output means 32 inputs a video signal, the primary color pixel data constituting one field is generated from the video signal. Then, the process proceeds to the next S102 “Calculates the pixel on-time of the high-luminance light emission period” (hereinafter abbreviated as S102), and the on-time of each pixel of the light valve element 20 in the high-luminance light emission period Th calculate.

  Proceeding to next step S104 “subtracting the pixel on time of the high luminance light emission period from the brightness to be displayed”, a process of subtracting the pixel on time of the high luminance light emission period from the brightness of each pixel to be displayed is performed, and the next S106 “ Proceed to “Calculate pixel on-time in low-luminance light-emission period from subtracted value” to calculate the on-time of the pixel in low-luminance light-emission period Tc.

  When the calculation of the on-time of each pixel in the high-luminance light emission period Th and the low-luminance light emission period Tc is completed, the calculated high-luminance light emission period Th and low are calculated in S108 “Output the on-time of each pixel to the light valve element”. The ON time of each pixel in the luminance light emission period Tc is output to the light valve element 20. In this manner, one color video in one field is generated, and the process proceeds to a process for generating the next color video.

  In the above description, the case where the video control signal output unit 32 executes the processing of S102 to S108 has been described. However, even if the information processing unit 180 executes the processing of S102 to S108, the object of the present invention is achieved. can do. When a liquid crystal display panel is used as the light valve element 20, a gradation signal is calculated and output to the light valve element 20 instead of the on-time of each pixel.

  Next, another embodiment of control signal generation processing by the video control signal output means 32 of the projection apparatus will be described with reference to FIG.

  When the video control signal output means 32 inputs a video signal, primary color pixel data constituting one field is generated from the video signal. Then, the process proceeds to the next determination of S202 “pixel brightness> high luminance light emission period”, and it is determined whether the brightness of each pixel is greater than the high luminance light emission period. If it is determined that the brightness of the pixel is greater than the high luminance light emission period, the process proceeds to the process of S206 “light valve element is driven in both the low luminance light emission period and the high luminance light emission period”. A process of generating a control signal for driving the pixel in both the low luminance light emission period Tc and the high luminance light emission period Th is performed. On the other hand, if it is determined that the pixel brightness is not greater than the high luminance light emission period, the process proceeds to S204 “pixel brightness> low luminance light emission period”.

  In S204, it is determined whether or not the brightness of each pixel is greater than the low luminance light emission period. If it is determined that the brightness of the pixel is greater than the low-luminance light emission period, the process proceeds to S208 “drive the light valve element in the high-luminance light emission period”, and the pixel of the light valve element 20 is Processing for generating a control signal to be driven only in the luminance light emission period Th is performed. On the other hand, if it is determined that the brightness of the pixel is not greater than the low-luminance light emission period, the process proceeds to S210 “drive the light valve element in the low-luminance light emission period”, and the pixel of the light valve element 20 emits low-luminance light. Processing for generating a control signal to be driven only in the period Tc is performed.

  When the generation processing of the control signal for driving the light valve element 20 is completed in S206, S208, or S210, the processing for generating the control signal is performed for each of the other pixels or other colors.

  In the above description, the case where the video control signal output unit 32 executes the processing of S202 to S210 has been described. However, even if the information processing unit 180 executes the processing of S202 to S210, the object of the present invention is achieved. can do.

  Next, an embodiment in which a bright image is generated by superimposing white light on an image generated using a plurality of primary colors will be described.

  FIG. 13 is a time chart showing a conventional field-sequential illumination light emission method for generating video in one field and three cycles. As shown in FIG. 13, in the conventional video generation method, videos of three colors of R, G, and B are sequentially generated, and video is generated in one field and three cycles by time mixing. In the lighting method shown in FIG. 13, the light sources of R, G, and B are lit for a period of 1/3 of one field, so the duty ratio is 1/3.

  FIG. 14 is a time chart showing a conventional field-sequential illumination light emission method for generating video in one field and four cycles. As shown in FIG. 14, even when a period in which the three colors R, G, and B are simultaneously turned on again is provided after an image is generated using the colors R, G, and B, one color is displayed for each color. As long as the light emitting diode is used, it cannot be lowered to 1/3 of the duty ratio shown in FIG. 13 due to the limitation of the lower limit of the duty ratio allowed for the light source.

  Therefore, in the embodiment of the present invention, as shown in FIG. 15, in addition to the light sources of the primary colors of R, G, and B, a white light source W for the purpose of improving the luminance of the image is added, and within one field. There is a period in which the white light source W is lit after each primary color of R, G, and B is emitted.

  FIG. 15 is a diagram showing an embodiment in which a period for turning on the white light source W is provided after light emission of each of the primary colors of R, G, and B. As shown in FIG. 15, in addition to the light sources of the primary colors R, G, and B, a white light source W for the purpose of improving the luminance of the video is added, and the lighting period of the primary color light emission period Tp and the white light emission period Tw. By providing this, the duty ratio can be reduced to about 1/4. Further, as shown in FIG. 15, by dispersing the lighting period of the white light source W, the efficiency related to heat radiation of the white light source W is increased, so that the amount of light emission can be increased. Therefore, it is possible to project a bright image with white added.

  For the white light added to the image, a luminance light quantity table in which the relationship between the luminance of one or a plurality of fields of the video or the average value thereof and the light emission quantity of each light source to be controlled is stored in the ROM 183 in advance, and the light emission control means It may be configured that the control unit 30 obtains the light emission amount by referring to the luminance light amount table, and controls to emit a plurality of primary colors simultaneously. By controlling the current supplied to the light source or the light emission time, the amount of emitted light can be easily controlled. In addition, the light emission control unit 30 may perform control to overlap a primary color light emission period in which a primary color light source emits light and a white light emission period in which a white light source emits light.

  Next, another embodiment in which a white light source W for the purpose of improving the luminance of an image is added will be described with reference to FIG.

  FIG. 16 is a diagram showing an embodiment in which a period in which the white light source W is turned on after the R, G, and B primary colors are continuously emitted in the primary color emission period Tp. As shown in FIG. 16, in addition to the primary color light sources of R, G, and B, a white light source W for the purpose of improving the luminance of the video is added, and the primary color emission period Tp and the white emission period Tw lighting period. By providing this, the duty ratio can be reduced to about 1/4. Therefore, it is possible to project a bright image with white added.

  Next, another embodiment in which a white light source W for the purpose of improving the brightness of an image is added will be described with reference to FIG.

  FIG. 17 shows a white light emission period Tw in which R, G, and B primary colors are continuously emitted in the primary color light emission period Tp and then the R, G, and B primary colors are emitted again and the white light source W is lit. It is a figure which shows embodiment provided. As shown in FIG. 17, in addition to the light sources of the primary colors of R, G, and B, a white light source W for the purpose of improving the luminance of the image is added, and the lighting period of the primary color light emission period Tp and the white light emission period Tw. By providing this, the duty ratio can be reduced to about 1/4. Therefore, it is possible to project a bright image with white added.

  Next, an embodiment of a projection apparatus 310 including a plurality of light sources 12 that emit primary colors and a light source 13 that emits white light will be described.

  FIG. 18 shows a video control signal output means in a projection apparatus 310 having a plurality of light sources 12 that emit primary colors and a light source 13 that emits white colors while the light sources 12 emit primary colors during the primary color emission period. FIG. 32 is a diagram illustrating a state in which an image is generated by outputting a control signal to the light valve element 20.

  Further, FIG. 19 shows that in the projection device 310 shown in FIG. 18, the video control signal output means 32 sends a control signal to the light valve element 20 while the light source 13 emits white light during the white light emission period. It is a figure which shows the state which has output and produced | generated the image | video. In the embodiment shown in FIG. 18 and FIG. 19, a device such as a DMD provided with an oscillating reflector having a first locking point and a second locking point for each pixel is used as the light valve element 20. When the reflection plate of the pixel is locked at the first locking point, the light emitted from the light source 12 during the primary color emission period is incident on the projection lens group 24 to project the image light. When the reflection plate of the pixel is locked at the second locking point, light emitted from the light source 13 during the white light emission period is incident on the projection lens group 24 to project image light, and the image is projected. The brightness of can be corrected.

  When a DMD is used as the light valve element 20 and the reflection plate of the DMD pixel has a locking point of ± θ symmetrical to the center of oscillation, the light emitted from the primary color light source 12 The light valve element 20 can be configured to illuminate the light emitted from the white light source 13 with different angles. In the embodiment shown in FIGS. 18 and 19, the light valve is formed at an angle at which the light emitted from the primary color light source 12 and the light emitted from the white light source 13 are symmetrical with respect to the optical axis incident on the projection lens group 24. The device 20 is configured to illuminate.

  In this way, by arranging the primary color light source 12 and the white light source 13 at different locations, it becomes easy to thermally insulate the primary color light source 12 and the white light source 13 from each other. Alternatively, when the light source shown in the time chart of FIG. 17 is controlled, it is possible to provide a bright image while suppressing the temperature rise of the light source. In order to control the light source shown in the time chart of FIG. 15, FIG. 16, or FIG. 17, the projection device 210 shown in FIGS. 9 and 10 can also be used. In this case, the primary color light source 12 is sequentially turned on in the primary color light emission period Tp to generate an image, and the primary color light source 12B is simultaneously emitted in the white light emission period Tw to generate white light. As shown in FIGS. 9 and 10, by arranging the light source 12 and the light source 12B at different locations and thermally insulating them, it is possible to suppress the temperature rise of the light source and provide a bright image.

  Next, another embodiment in which a white light source W for the purpose of improving the luminance of an image is added will be described with reference to FIG.

  FIG. 20 shows an implementation in which light sources of primary colors R, G, and B are continuously emitted in the primary color emission period Tp1, and then light sources of different primary colors R, G, and B are emitted in the primary color emission period Tp2. It is a figure which shows the form of. As shown in FIG. 20, in addition to the light sources of primary colors R, G, and B, light sources of primary colors R, G, and B for the purpose of improving the luminance of an image are added, and the first primary color emission period By providing lighting periods of Tp1 and the second primary color light emission period Tp2, the duty ratio can be reduced to about 1/6. Therefore, a bright image can be projected. In the embodiment shown in FIG. 20, the light emission order of each primary color is light emission in the order of R1, G1, B1, R2, G2, B2, but R1, R2, G1, G2, B1, B2, B2 You may comprise so that it may light-emit in order.

  Note that the projection apparatus 210 shown in FIGS. 9 and 10 can be used as a configuration example of a light source for controlling the light source shown in the time chart of FIG. In that case, in the projection device 210 shown in FIG. 9, the video control signal output means 32 first outputs the light valve element 20 to the light valve element 20 while the light source 12 emits the primary color in the first primary color light emission period Tp1. Output a control signal to generate an image. Next, while the light source 12B emits the primary color in the second primary color emission period Tp2, the video control signal output unit 32 outputs a control signal to the light valve element 20 to generate a video. In this way, the light source 12 and the light source 12B are disposed at different locations and thermally insulated, and a plurality of sets of primary color light sources are sequentially turned on in one field, thereby suppressing a temperature rise of the light source and bright images. It becomes possible to provide.

  Next, an embodiment in which the amount of light of a projected image is corrected according to the projection distance by using a projection device including a plurality of light sources 12 that emit primary colors and a light source 13 that emits white light will be described.

  FIG. 21 is a diagram illustrating the relationship between the projection distance and the light amount correction amount of the projected image.

  As shown in FIG. 21, when the brightness of the projected image when the projection distance is 1.5 m is 1 (reference), the brightness of the image before correction becomes darker as the projection distance is longer. Therefore, by adding a white correction amount to the image light according to the projection distance, an image with a constant brightness can be projected regardless of the distance.

  FIG. 22 is a chart showing the relationship between the projection distance and the light amount correction amount of the projected image.

  When DMD is used as the light valve element 20, for example, white light corresponding to the projection distance as shown in FIG. 22 can be added to make the brightness of the image constant regardless of the projection distance. If the change in the projection distance is large, there is a possibility that the contrast of the image cannot be sufficiently obtained by adding a large amount of white light. Therefore, it is not always necessary to keep the brightness of the image constant.

  For deriving the chart shown in FIG. 22, it is used that the brightness of the image is inversely proportional to the square of the projection distance. The projection light correction amount is obtained by dividing how many times the light source should be given to the light source so that the brightness of the projection light is the same (100%) as the reference brightness. When white light is not added, it is assumed that the primary colors of R, G, and B have a brightness of 1/3 for a period of 1/3, and the correction amount at this time is 100%.

  Therefore, if the time for adding white light is x (%) and the correction amount is y (%), the relational expression x = (y−1) / 8 can be obtained.

  Next, an embodiment of a process for correcting the amount of light of a projected image using a projection apparatus including a plurality of light sources 12 that emit primary colors and a light source 13 that emits white light will be described with reference to FIG.

  FIG. 23 is a flowchart of processing for detecting the projection distance and adding white light after the projection apparatus is activated.

  When the projection apparatus 310 is turned on and the projection apparatus 310 is in a use state, the processing executed by the information processing means 180 proceeds to S302 “startup processing”, and initial setting of each peripheral circuit is executed. When the activation processing of these projection devices 310 is completed, the processing executed by the information processing means 180 proceeds to the next S304 “Detection of projection distance from button operation”, and relates to the projection distance input by the user via the input means 170. Detect information.

  In the next step S306 “Set white value according to table value”, the information processing means 180 acquires the white light additional ratio according to the projection distance and turns on the white light source 13 for the white light emission period Tw. Is output to the light emission control means 30. For the white light addition ratio, for example, chart data as shown in FIG. 22 is stored in the ROM 183 in advance, and the white light addition ratio is acquired using the projection distance input through the input unit 170. Can do.

  In the next S308 “Power OFF?”, The information processing means 180 determines whether or not the power switch of the projection apparatus 310 is turned off. If the power switch has not been turned off, the process returns to S304. If it is determined that the power switch has been turned off, the process proceeds to the next S308 “End of process”.

  In S <b> 308, the information processing unit 180 performs a shutdown process of the projection apparatus 310, proceeds to the next S <b> 312 “Power OFF”, and performs a process of shutting down the power supply of the projection apparatus 310. As described above, it is possible to correct the light amount with respect to the projection distance.

  Next, another embodiment of a projection apparatus having a low luminance light emission period and a high luminance light emission period will be described with reference to FIG.

  FIG. 24 is a block diagram showing an internal configuration of a projection apparatus 410 using a reflective liquid crystal panel as the light valve element 20. Note that components having the same functions as those of the projection apparatus 10 shown in FIG. 1 are denoted by the same reference numerals, and description of the functions is omitted.

  In the embodiment shown in FIG. 24, since the reflective liquid crystal panel is used as the light valve element 20, the polarization beam splitter 36 and the polarization conversion element 34 are used in the illumination optical system.

  For example, the polarization conversion element 34 has the structure shown in FIG. 25, and from the light source side, a P wave (a polarization component whose electric field component is parallel to the incident surface) and an S wave (the electric field component is perpendicular to the incident surface). In this structure, only the S wave is emitted.

  As shown in FIG. 25, when a P wave and an S wave are incident from the light source side, the P wave is transmitted by the polarization separation film and the S wave is reflected. The transmitted P wave is emitted as an S wave by rotating a 90-degree electric field component by the 1 / 2λ plate. On the other hand, the S wave reflected by the polarization separation film is further reflected by the polarization separation film and emitted as it is with the electric field component.

  When the polarization beam splitter 36 receives S-wave illumination light obtained by combining the light beams of the primary colors, the S-wave illumination light is reflected by the polarization separation film and applied to the light valve element 20. The light valve element 20 reflects the S-wave light emitted from the polarization beam splitter 36 according to the brightness of the image along the liquid crystal molecules and reflects the light, and then enters the polarization beam splitter 36 again. The polarization separation film of the polarization beam splitter 36 transmits only the P wave and reflects the S wave in the image light incident from the light valve element 20. The image light generated in this way is incident on the projection lens group 24 and the image is projected onto the screen 26.

  As shown in FIG. 24, the projection apparatus 410 is configured, and the light emission control unit 30 time-divides the primary color light source 12 to emit light at low luminance, and the plurality of primary color light sources 12 are time-divided. A light emission signal having a high luminance light emission period Th that emits light with high luminance is output to the light source 12, and the video control signal output means 32 outputs a light amount correction signal in both the low luminance light emission period Tc and the high luminance light emission period Th. Is output to the light valve element 20, and the lighting time of the light source in one field of the video can be lengthened while intermittently lighting the light source to secure the heat radiation time. Therefore, it is possible to increase the light quantity of the video generated by the video generation device while suppressing the temperature rise of each light source. In addition, by temporally mixing the video generated in the low luminance light emission period Tc and the video generated in the high luminance light emission period Th, gradation display can be performed in a short sector time, and the frame rate can be improved. it can.

  Next, another embodiment of the projection apparatus having the primary color light emission period Tp and the white light emission period Tw will be described with reference to FIG.

  FIG. 26 is a block diagram showing an internal configuration of a projection apparatus 510 using a reflective liquid crystal panel as the light valve element 20. Of the components shown in this block diagram, components having the same functions as those of the projection apparatus shown in FIGS. 18 and 25 are denoted by the same reference numerals, and description of the functions is omitted.

  In the embodiment shown in FIG. 26, in order to irradiate the light valve element 20 with a primary color for generating an image and white light for improving the luminance of the image, two polarization beam splitters 36 and 38, A polarization conversion element 34 and one polarization conversion element 35 are used.

  The two polarization conversion elements 34 used in the projection device 510 are elements that emit only S waves. One polarization conversion element 35 is configured to emit only P waves.

  When the polarization beam splitter 38 receives P-wave illumination light obtained by combining the primary color lights from the polarization conversion element 35, the P wave travels straight and enters the polarization conversion element 34. On the other hand, when the polarization beam splitter 38 enters illumination light from the polarization conversion element 34 on the white light source 13 side, the S-wave illumination light is reflected by the polarization separation film and emitted to the polarization conversion element 34 on the polarization beam splitter 36 side. To do. The polarization conversion element 34 provided between the polarization beam splitter 36 and the polarization beam splitter 38 emits an S wave to the polarization beam splitter 36.

  The polarization beam splitter 36 reflects the S-wave illumination light incident from the polarization conversion element 34 by the polarization separation film and irradiates the light valve element 20. The light valve element 20 reflects the S-wave light emitted from the polarization beam splitter 36 according to the brightness of the image along the liquid crystal molecules and reflects the light, and then enters the polarization beam splitter 36 again. The polarization separation film of the polarization beam splitter 36 transmits only the P wave and reflects the S wave in the perpendicular direction among the image light incident from the light valve element 20. Therefore, the image light synthesized with the white light can enter the projection lens group 24 and the image can be projected onto the screen 26. In addition, as each said light source 12 and 13, a high-intensity light emitting diode or laser diode can be used.

  As shown in FIG. 26, the projection apparatus 510 is configured, and the light emission control unit 30 includes a primary color light emission period Tp in which the primary color light source 12 emits light in a time division manner and a white light emission period Tw in which the white light source 13 emits light. The light emission signal is output to the light sources 12 and 13, and the video control signal output means 32 outputs the light amount correction signal to the light valve element 20 in both the primary color light emission period Tp and the white light emission period Tw. The light source shown in the time chart of FIG. 16 or FIG. 17 can be controlled, and the lighting time of the light source in one field of the video can be extended while reducing the duty ratio at which the light source is turned on. Therefore, it is possible to increase the light quantity of the video generated by the video generation device while suppressing the temperature rise of each light source.

  In addition, as shown in FIG. 26, by arranging the primary color light source 12 and the white light source 13 in different locations, it becomes easy to thermally insulate the primary color light source 12 and the white light source 13 from each other. Therefore, it is possible to provide a bright image while suppressing the temperature rise of the light source. In the embodiment shown in FIG. 24 and FIG. 26, the embodiment using the reflective liquid crystal display panel as the light valve element 20 is shown, but a transmissive liquid crystal panel can also be used.

  Next, the amount of illumination light when each light source emits light will be described using the time chart of FIG.

  The luminance when the white light source W is kept on for one field is set to 1, and the efficiency of the polarization conversion element is set to 2/3. Also, in order to explain the event simply, the length of each sector is assumed to be equal. In the case of the prior art shown in FIG. 14, the red light source is lit at an intensity of 1/3 in 1/3 time of one field, and this illumination light passes through the polarization conversion element once. And 2/27 strength. Similarly, green and blue illumination lights have an intensity of 2/27, so that a total luminance of 2/9 can be obtained.

  On the other hand, in the embodiment of the present invention shown in FIG. 17, each illumination light of red, green, and blue can be lit at an intensity of 1/4 in a period of 1/4 of one field. In addition, since the light passes through the polarization conversion elements 34 and 35 of the projection apparatus 510 shown in FIG. 26, 2/3 is multiplied twice to obtain the luminance of each color 1/27. When red, green, and blue are added together, the luminance is 1/9. Further, the light emission period of white light can be turned on for a period of 1/4 of one field at an intensity of 1, and the red, green and blue light sources 12 can also be turned on. Therefore, when the white light emission period is combined with the red, green, and blue light emission periods, the brightness is 1/3, and illumination light with a brightness higher than 2/9 can be irradiated. In addition, since red and blue have low specific visibility, there is actually a greater difference.

  When the luminance at the time of controlling the time chart shown in FIG. 16 is calculated by the above calculation, the luminance of 2/9 similar to that of the prior art shown in FIGS. 13 and 14 is calculated. Since the current supplied to the light source can be increased when the duty ratio is ¼ than when the duty ratio is ３, the time chart shown in FIG. 16 is actually used. Higher luminance can be obtained by using this method to generate an image.

It is a block diagram which shows the internal structure of the projection apparatus of one form of the image | video production | generation apparatus which concerns on this invention. It is a time chart showing the timing of the video generation signal in the low luminance light emission period Tc and the timing of the light amount correction signal in the high luminance light emission period Th. It is a time chart which performs control which makes the light source 12 light-emit during the high-intensity light emission period Th. It is a time chart which shows embodiment which provided the 2nd high-intensity light emission period Th after the 1st low-intensity light emission period Tc, and provided the 3rd low-intensity light emission period Tc after that. After the light source 12 of primary colors of red, green, and blue is sequentially emitted with low luminance to generate one field of the image, the light source 12 of primary colors of red, green, and blue is sequentially emitted with high luminance. It is a time chart which shows embodiment. It is a time chart which shows embodiment which provides a middle-intensity light emission period Tm in addition to the low-intensity light emission period Tc and the high-intensity light emission period Th, and performs a gradation display. It is a time chart which shows embodiment which provides the low-intensity light emission period Tc, the medium-intensity light emission period Tm, and the high-intensity light emission period Th, and performs a gradation display. It is a figure which shows embodiment of the projector 110 provided with two independent light emission sources in one light source 12A. It is a figure which shows the state which produces | generates an image | video, while the light source 12 is light-emitting primary color in the low-intensity light emission period Tc. It is a figure which shows the state which produces | generates an image | video, while the light source 12B is light-emitting primary color in the high-intensity light emission period Th. It is a flowchart which shows embodiment of the production | generation process of the control signal of the light valve element 20 which the video control signal output means 32 of a projector performs. It is a flowchart which shows other embodiment of the production | generation process of the control signal of the light valve element 20 which the video control signal output means 32 of a projection apparatus performs. It is a time chart which shows the light emission method of the illumination light of the conventional field sequential system which produces | generates an image | video in 1 field 3 cycles. It is a time chart which shows the light emission method of the conventional field sequential type illumination light which produces | generates an image | video in 1 field 4 cycles. It is a figure which shows embodiment which provides the period which turns on the white light source W after light emission of each primary color of R, G, B. It is a figure which shows embodiment which provides the period which turns on the white light source W after light-emitting each primary color of R, G, and B continuously. It is a figure which shows embodiment which provides the period which light-emits each primary color of R, G, and B again after having light-emitted each primary color of R, G, and B again, and turns on the white light source. It is a figure which shows the state which the image | video control signal output means 32 outputs the control signal with respect to the light valve element 20, and produces | generates an image | video, while the light source 12 is light-emitting primary color in the primary color light emission period. It is a figure which shows the state which the image | video control signal output means 32 outputs the control signal with respect to the light valve element 20, and produces | generates an image | video, while the light source 13 is light-emitting white in the white light emission period. It is a figure which shows embodiment which provides the period which light-emits the light source of each primary color of R, G, B after light-emitting of the primary color light source of R, G, B continuously. It is a figure which shows the relationship between a projection distance and the light quantity correction amount of a projection image | video. It is a graph which shows the relationship between a projection distance and the light quantity correction amount of a projection image. It is a flowchart of the process which detects a projection distance and adds white light after starting of a projection apparatus. 3 is a block diagram showing an internal configuration of a projection apparatus 410 using a reflective liquid crystal panel as a light valve element 20. FIG. 3 is a side view showing the structure of a polarization conversion element 34. FIG. 3 is a block diagram showing an internal configuration of a projection apparatus 510 using a reflective liquid crystal panel as a light valve element 20. FIG.

Explanation of symbols

10, 110, 210, 310, 410, 510 Projector 12, 12A, 12B, 13 Light source 14 Condenser lens 16 Dichroic mirror 20 Light valve element 22, 22B Mirror 24 Projection lens group 26 Screen 30 Light emission control means 32 Video control signal output Means 34, 35 Polarization conversion element 36 Polarization beam splitter 170 Input means 180 Information processing means 181 RAM
183 ROM
190 Time measuring means 191 Angle of view detection means 192 Projection angle acquisition means 199 Bus Tc Low luminance light emission period Tm Medium luminance light emission period Th High luminance light emission period Tp Primary color light emission period Tw White light emission period Tr Image generation signal Hr Light quantity correction signal

Claims (36)

One field of video is divided into sectors corresponding to different primary colors, a light valve element for generating video corresponding to the primary color during each sector period, and low-luminance light of the primary color during each sector period A first light source for irradiating the light valve element; a second light source for irradiating the light valve element with high-luminance light of the primary color during each sector; and a light emission signal for controlling the amount of light emitted from the light source. A light emission control means for outputting a video signal and a video control signal output means for inputting a video signal and outputting a control signal to the light valve element, and a video generation device for generating a high-luminance color video by time mixing,
The light emission signal output by the light emission control means has a low luminance light emission period in which the first light source emits light and a high luminance light emission period in which the second light source emits light within the period of the one field,
The control signal output from the video control signal output means controls the amount of light emitted from the light source during the low luminance light emission period and controls the amount of light emitted from the light source during the high luminance light emission period.   The light emission control means drives the first light source with substantially the same pulse width as the sector period which is each light emission period of RGB light when irradiating the RGB light from the first light source in a time division manner, and The video generation apparatus according to claim 1, wherein the second light source is driven with a pulse width shorter than the sector period.   3. The image generation apparatus according to claim 2, wherein the light emission control unit drives the first light source at a continuous rated current or less and drives the second light source at a current larger than the continuous rated current.   4. The image generation apparatus according to claim 1, wherein the first light source and the second light source are configured by light-emitting diodes that are pulse-driven.   4. The image generating apparatus according to claim 1, wherein the first light source and the second light source are configured by pulsed laser light emitting elements. 5.   The image generation device according to claim 1, wherein a light emitting diode is used as the first light source and a laser diode is used as the second light source.   The video according to claim 1, wherein the light emission control unit performs control to overlap a low luminance light emission period in which the light source of the primary color emits light with low luminance and a high luminance light emission period in which the primary color emits light with high luminance. Generator.   The video generation device according to claim 1, wherein light sources of three primary colors of red, green, and blue are used as the second light source.   2. The light emission control means performs control for emitting the primary color with an amount of light for inputting the video signal, extracting a maximum luminance in one or a plurality of fields of the video, and projecting at the extracted maximum luminance. The video production | generation apparatus of any one of -8.   The image generation apparatus according to claim 9, wherein the light emission control unit controls the light emission time of the light source in the high luminance light emission period when controlling the amount of light for projecting the maximum luminance in one field of the image.   The said light emission control means controls the electric current supplied to the said light source in the said high-intensity light emission period, when controlling the light quantity for projecting the maximum brightness | luminance in 1 field of an image | video. Video generation device.   The light emission control means causes the second high-luminance light emission to cause the second light source of the second primary color to emit light with high luminance after the first low-luminance light emission period for causing the first light source of the first primary color to emit light with low luminance. The video generation device according to any one of claims 1 to 11, wherein a period is provided, and then a control is performed to provide a third low-luminance light emission period for causing the first light source of the third primary color to emit light with low luminance.   13. The light emission control unit performs control for sequentially emitting light of each primary color second light source with high luminance after the first light source of each primary color is sequentially emitted with low luminance to generate one field of an image. The video generation device according to any one of the above.   The said light emission control means performs control which provides the high-intensity light emission period which light-emits the said 2nd light source of primary color with high brightness immediately after the low-intensity light emission period which light-emits the 1st light source of predetermined primary color with low brightness. The video production | generation apparatus of any one of 1-11.   The said light emission control means performs control which provides the low-intensity light emission period which makes the 1st light source of the said primary color light-emit with low brightness immediately after the high-intensity light emission period which light-emits the 2nd light source of predetermined primary color with high brightness. The video production | generation apparatus of any one of 1-11.   The image generation signal output means adjusts the gradation of an image for each pixel by outputting an image control signal for generating an image using light of both low luminance and high luminance to the light valve element. Item 16. The video generation device according to any one of Items 1 to 15. One field of video is divided into sectors corresponding to different primary colors, a light valve element for generating video corresponding to the primary color during each sector period, and a plurality of types of luminance of the primary color during each sector period A light source for irradiating the light valve element with light, a light emission control means for outputting a light emission signal for controlling the light emission amount of the light source, and a video control signal for inputting a video signal and outputting a control signal to the light valve element An image generating apparatus that generates a color image by temporal color mixing of a plurality of types of primary colors with output means,
The light emission signal output from the light emission control means includes a signal for causing the primary color light source to emit light with a plurality of different luminances within the period of the one field.
The control signal output by the video control signal output means is a video generation device that controls the amount of light emitted by the light source at the plurality of different brightness levels.   The video generation apparatus according to claim 17, wherein the light emission control unit includes a pulse driving unit that performs control to cause the light source to emit light with a plurality of types of luminance by controlling a current supplied to the light source. One field of video is divided into sectors corresponding to different primary colors, a light valve element for generating a video corresponding to the primary color during each sector period, and light of the primary color during the period of each sector A light source for irradiating an element, a white light source for irradiating the light valve element with white light, a light emission control means for outputting a light emission signal for controlling a light emission amount of the light source, and a light signal input to the light valve element And a video control signal output means for outputting a control signal to a video generation device for generating a color video by temporal color mixing and generating a high brightness video by adding white light,
The light emission signal output by the light emission control means has a primary color light emission period for emitting the primary color light source and a white light emission period for emitting the white light source within the period of the one field,
The control signal output by the video control signal output means controls a video generated by the light valve element during the primary color light emission period and controls a video generated by the light valve element during the white light emission period. .   20. The image generation apparatus according to claim 19, wherein a plurality of primary color light sources are used as the white light source, and white light is generated by simultaneously emitting light from the plurality of primary color light sources.   21. The image generation according to claim 19 or 20, wherein the light emission control unit performs a control of emitting light of the white light source after sequentially emitting light of all primary colors in one field of the image in a time division manner. apparatus.   The said light emission control means performs control which light-emits all the said primary color light sources and the said white light source, after making it light-emit one by one by time-sharing all the primary color light sources within one field of an image | video. Item 20. The video generation device according to Item 20.   The light emission control means provides a white light emission period in which a white light source emits light after a first primary color light emission period in which the first primary color light source emits light, and then causes a second primary color light source to emit light. The video generation device according to claim 19 or 20, wherein control for providing a primary color emission period is performed.   21. The image generation apparatus according to claim 19 or 20, wherein the light emission control unit performs control to emit light of a white light source after sequentially generating light of each primary color to generate one field of an image.   The light emission control unit is configured to input the video signal, extract a maximum luminance in one or a plurality of fields of the video, and perform control to cause the white light source to emit light with a light amount for projection with the extracted maximum luminance. Item 25. The video generation device according to any one of Items 19 to 24.   26. The image generation apparatus according to claim 25, wherein the light emission control unit controls a light emission time of a white light source in the white light emission period when controlling a light amount for projecting a maximum luminance in one field of the image.   27. The video generation apparatus according to claim 25, wherein the light emission control unit controls a current supplied to the white light source when controlling a light amount for projecting a maximum luminance in one field of the video.   The video generation according to any one of claims 19 to 27, wherein the light emission control unit performs control to overlap a primary color light emission period in which the primary color light source emits light and a white light emission period in which the white light source emits light. apparatus.   The image generation device according to any one of claims 19 to 28, wherein a DMD (Digital Micromirror Device) is used for the light valve element. The light source independently includes a first light source that emits the primary color with low luminance during the low luminance emission period, and a second light source that emits the primary color with high luminance during the high luminance emission period,
30. The image generating device according to claim 29, wherein the light valve element illuminates the light valve element with light emitted from the first light source and light emitted from the second light source at different angles.   The image generation device according to claim 30, wherein the light valve element illuminates light emitted from the first light source and light emitted from the second light source at symmetrical angles.   32. The image generation device according to claim 19, wherein a light emitting diode is used as the light source.   32. The image generation device according to claim 19, wherein a laser diode is used as the light source.   19. The video generation device according to claim 1, wherein a DMD (Digital Micromirror Device) is used for the light valve element.   The image generation device according to any one of claims 1 to 28, wherein a transmissive or reflective liquid crystal display element is used as the light valve element.   36. The image generating device according to claim 35, further comprising a polarization conversion element or a polarization beam splitter between the light source and the light valve element.

Images