JP2005300832A - Image projection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image projection apparatus capable of obtaining a uniform image with little unevenness and an image in which flicker, that is time unevenness, is few by following an input when starting time variations of input frame-unit image information and jitter are included. <P>SOLUTION: The apparatus comprises; a light source unit part 34 in which a plurality of LEDs 18 with one body structure for emitting an illumination light are arranged on circumference and which sequentially turns on each LED 18; a spacial modulation element 46 which is modulated according to the input frame-unit image information; a light guide rod member 12 which leads illumination light emitted by the LEDs 18 which are sequentially turned on, to the spacial modulation element 46 by synchronizing with a turn-on timing of the plurality of LEDs 18 and by moving relatively with the plurality of LEDs 18; and a read-out timing controller 42 for controlling a frame timing of the image information which is modulated by the spacial modulation element 46. The read-out timing controller 42 controls the frame timing of the image information which is modulated by the spacial modulation element 46 by synchronizing with a relative moving timing of the plurality of LEDs 18 and the light guide rod member 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is an image projection apparatus that projects an image according to image information in units of input frames, and in particular, collects light by arranging light emitting elements such as LEDs in a ring shape and rotating an optical rod. The present invention relates to an image projection apparatus using a light source unit.

  There are no other prior examples that are similar in structure to the present invention, but the following two cases are mentioned.

  First, there is Patent Document 1 that discloses a light source unit section in which light-emitting elements such as LEDs are arranged and rotated in a ring shape and condensed by a fiber. In this light source unit, the LED emission pulse and the rotation phase of the LED unit are associated with the synchronization signal of the video signal, and the synchronization signal is a synchronization signal for driving the photographing camera, Since it synchronizes with the clock of the timing controller and does not have jitter in the first place, the problem that the present invention poses does not occur.

Secondly, Patent Document 2 discloses a projector that uses a color wheel in which a plurality of color filters are configured as one disk and a digital micromirror device (DMD (trademark)) as a spatial modulator. It is done. This Patent Document 2 describes the configuration and control of a frame memory for adjusting the phase of input video data to the rotation phase of the color wheel and the DMD drive data. However, since the light emitting element is not composed of a large number of light emitting elements, there is no problem of unevenness in the screen due to variations in the light amount of each light emitting element.
JP 2003-24275 A JP-A-8-051638

  The present invention is to solve the problem in a projector using a light source unit that collects light by arranging light emitting elements such as LEDs in a ring shape and rotating an optical rod. That is, since the optical rod is mainly made of glass or the like, it has a large weight and a large moment of inertia. Therefore, there is a problem that it is difficult to follow the input when it includes fluctuations at start-up such as a video reproduction signal and jitter.

  Since the light source unit collects light beams from the individual light emitting elements while the optical rod moves, the amount of light output from the light source unit varies with time in one rotation. For this reason, the projection image of a projector using this light source unit basically has unevenness in the amount of light on the screen, and if the rotation speed changes finely within one rotation even if the time for one rotation does not change, There exists a subject that the noise which a nonuniformity moves generate | occur | produces.

  In addition, in the case of a lighting method in which the light emitting element emits light only when passing through the rod in such a projector, the amount of light obtained in one rotation changes when the time required for one rotation changes, and the amount of light in a frame unit is used as a projection image. Flicker is likely to occur as a fluctuation.

  Furthermore, in the case of the frame sequential method in which RGB light emitting elements are arranged in order on the same circumference and the frame images of each color are displayed in order during one rotation, the problem of color flicker and the signal for controlling the spatial modulation element There is also a problem of deterioration of color reproducibility due to deviation of the color element pair of the light source and the color element of the light source.

  FIG. 10 shows fluctuations in the amount of light emitted from the light source and phase fluctuations in the input video signal. In the image projection apparatus assumed by the present invention, the light emission pulses for individually emitting the LEDs arranged in a ring shape are sequentially turned on sequentially so that the optical rods drive the light from the individual LEDs emitting light. By rotating and condensing, a light emission amount as illumination light can be obtained. In the image projection apparatus having such a configuration, as shown in the figure, the light emission pattern has a pulsation that maximizes the amount of light when the optical rod passes through the peak position of the spatial light distribution of the LED. Actually, there is a variation in the amount of light emitted from individual LEDs, so that the number of times corresponding to the number of LEDs used varies. When there is no fluctuation such as jitter in the phase of the input video signal, the sync signal of the light emission pulse and the input video signal is synchronized locally, but when there is a phase fluctuation, it is relatively synchronized with the light emission pulse. The signal fluctuates.

  When a transmissive LCD or the like is used as the spatial modulation element, an arbitrary display on the screen of the spatial modulation element is possible as long as the sync signal is relatively stable and the phase does not vary even if the amount of light emitted from the individual LEDs varies. The frame interval from the setting of the video data of the pixel to the next rewriting is constant between the pixels, and the integrated light amount illuminated on each pixel shown in FIG. Variation does not appear directly as unevenness in the screen. On the other hand, when the synchronization signal relatively changes, the frame interval of the arbitrary display pixel on the screen of the spatial modulation element changes, so that the difference between the integrated light quantities appears as the area ΔS. This area ΔS is not simply proportional to the time from the variation in the amount of emitted light and the pulsation of the individual LEDs, so that there is a problem that the unevenness correction means requires real-time properties and the correction processing becomes complicated.

  When using a device that performs PWM control of video data such as DMD (trademark) as a spatial modulation element, light emission due to the peak position of the spatial light distribution of the LED and the passage of the optical rod, even if there is no variation in the light emission amount of the individual LED Unevenness occurs due to the relationship between the pulsation pattern of the light amount and the PWM on / off operation phase. In addition to this unevenness, unevenness due to fluctuations in the sync phase of the input video signal, LED light emission pulse, and optical rod also occurs in the same way as in the case of the above transmissive LCD, etc. There is.

  The present invention has been made in view of the above points, and follows input when there is a start-up variation or jitter in image information in units of input frames. An object of the present invention is to provide an image projection apparatus capable of obtaining an image with a small flicker.

One aspect of the image projection apparatus of the present invention is an image projection apparatus that projects an image according to input image information in units of frames,
A plurality of LED light sources configured as an integral unit for emitting illumination light are arranged on the circumference, and a light source unit unit that sequentially lights each LED light source in time series,
A spatial modulation element that is modulated in accordance with input frame-unit image information;
Illumination optical means for illuminating the spatial modulation element by guiding the illumination light emitted by the light source unit,
Timing control means for controlling frame timing of image information modulated by the spatial modulation element;
Comprising
The illumination optical means includes LED light sources that are synchronized with the lighting timings of the plurality of LED light sources and that move relative to the plurality of LED light sources, so that the LED light sources sequentially light in time series. Is directed to the spatial modulation element.
The timing control means controls frame timing of image information modulated by the spatial modulation element in synchronization with relative movement timings of the plurality of LED light sources and the light guide means.

  According to the present invention, it is possible to obtain a uniform image with less unevenness and an image with less flicker that is uneven in time when the input frame-unit image information includes fluctuation at start-up and jitter. A possible image projection apparatus can be provided.

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

[First Embodiment]
FIG. 2A is a diagram showing a configuration of the light source unit in the image projection apparatus according to the first embodiment of the present invention, and FIG. 3 is a block diagram showing an electrical configuration of the light source unit. Note that FIG. 2B is a cross-sectional view taken along the line AA in FIG.

  That is, the light source unit in the present embodiment includes a light guide rod member 12 that is a rectangular light guide means that is configured by a T-shaped optical surface attached to a rod holder 10 that is a rotatable holder. The LED 18 as a plurality of light emitters, which are rotated by a rotary motor 14 as a driving means and arranged on the inner periphery of the LED substrate 16 formed in a drum shape, is sequentially turned on in accordance with the rotation of the light guide rod member 12.

  The light guide rod member 12 is made of an optical surface that satisfies the total reflection condition so that the light guide rod member 12 is made of glass or resin that is transparent with respect to the wavelength range of the illumination light beam, and is guided by total reflection on the side surface from the viewpoint of efficiency. (An optical surface that has been mirror-finished on the entire surface may be used). Here, the T-shaped light guide rod member 12 may be manufactured by integral molding, or, as shown in FIG. 2B, a prismatic parallel rod 12A and an inclined surface for bending the optical path are provided with a reflective coat. You may join and form 5 parts of the reflecting prism 12B and the taper rod 12C which gave.

  The LEDs 18 having red (R), green (G), and blue (B) emission colors are arranged on the inner periphery of the drum-shaped LED substrate 16 with a predetermined number of each set as one set. .

  With this configuration, the light source unit illuminates an illuminated area (not shown) using the emission end face of the light guide rod member 12 as a virtual light source.

  Further, in the light source unit portion, a rotation sensor 20 for detecting the rotational position of the rod holder 10 is disposed near the side surface of the rod holder 10. As the rotation sensor 20, for example, a photo reflector is used, and a single reflector attached to the side surface of the rod holder 10 or switching of each color group in which the plurality of LEDs 18 are arranged on the side surface of the rod holder 10 is used. A device that detects one rotation of the rod holder 10 or a color group position or the like by detecting light reflected by a plurality of reflecting plates that are attached to the position or the position that matches the interval between the LEDs 18 can be used. The rotation detection / color group information by the rotation sensor 20 is input to the motor drive control circuit 22 and the light emission timing control circuit 24.

  Here, the motor drive control circuit 22 controls the rotation motor 14 and constitutes a movable means for driving the light guide rod member 12 to rotate together with the rotation motor 14. That is, the motor drive control circuit 22 starts the rotation of the rotary motor 14 when an operation start signal is input in accordance with a button operation or the like by a user, and the rotation sensor 20 detects the rotational position of the rod holder 10 according to the rotation position detection result. Drive control is performed so that the rotation motor 14 rotates at a constant speed.

  The light emission timing control circuit 24 generates a timing signal based on the rotation position detection of the rod holder 10 by the rotation sensor 20 and inputs the timing signal to the drive LED selection circuit 26. The drive LED selection circuit 26 constitutes a lighting circuit sequentially with each LED drive circuit 28 for driving each LED 18 mounted on the LED board 16 in accordance with the input timing signal. By selectively giving a drive control signal to the circuit 28, the light intake port 12I of the light guide rod member 12, that is, the LED 18 at the position of the incident surface of the parallel rod 12A is controlled to be turned on sequentially. At this time, the LED 18 drive current by the LED drive circuit 28 is controlled by the LED drive current control circuit 30 so that the light emission amount of the LED 18 is optimized.

  In addition, a heat sink 32 is provided on the outer periphery of the drum-shaped LED substrate 16 to dissipate heat generated by light emission of the LED 18, thereby preventing changes in the characteristics of the LED 18 due to heat, and the illumination device. Stable lighting can be obtained even if the is operated continuously.

  In this way, by sequentially switching the plurality of LEDs 18 to emit pulsed light and changing the relative positional relationship with the light guide rod member 12 that takes in the radiated light together with the light emission switching of the LEDs 18, the light guide rod members are respectively changed. The light emission amount of the LED 18 is controlled to be optimal by a process circuit in which the 12 rotates once. The color of the emitted light is switched in the order of red (R) color, blue (B) color, green (G) color, red (R) color, blue (B) color, and green (G) color. The LEDs 18 of three colors with luminance are obtained, and three colors of light with improved parallelism with a large amount of light can be obtained from the exit end face of the light guide rod member 12. Note that the order of the emission colors is not limited to the above, and may be set as appropriate.

  In this configuration, the relative position shift between the LED 18 and the light guide rod member 12 is performed by rotating the light guide rod member 12, but it can also be realized by moving the LED 18. However, it is preferable to move the light guide rod member 12 from the viewpoint of power supply to the LED 18.

  Further, when the LED 18 fails, as shown in FIG. 3, the entire LED board 16 including the failed LED can be replaced.

  FIG. 1A is a diagram showing the overall configuration of the image projection apparatus according to the present embodiment including the light source unit 34 and the video signal processing unit configured as described above, and FIG. It is a figure which shows the detail of a structure of a light source unit part and a read-out timing controller for demonstrating the video signal processing method based on the timing signal from the light source unit part.

  In FIG. 1A, an analog RGB signal output from a personal computer or the like is converted into digital data of a predetermined bit by a video front end unit 36. Similarly, a video signal of a television (NTSC) or the like is converted into digital data after being subjected to synchronization separation and Y / C separation in the video front end unit 36 according to the input signal form. The video data thus converted into digital data is input to the digital signal processing unit 38. When the video signal is an interlace signal, the digital signal processing unit 38 may perform IP conversion (interlace → progressive) processing. The digitally converted video data (IP converted as necessary) is subjected to predetermined processing such as de-γ processing, scaling (resolution conversion), and color space conversion. The above is a general video signal processing process when an input signal is displayed on a display device.

  In the present embodiment, the digitally converted video data is further time-divided for each of red (R), blue (B), and green (G) and then written to the frame memories 40R, 40G, and 40B. . The video data written in the frame memories 40R, 40G, and 40B is read by a predetermined frame memory read clock supplied from the read timing controller 42, and supplied to the driver unit 44 as a rate conversion video signal. The read timing controller 42 functions as a timing control means, and generates a timing control signal to be supplied to the frame memory read clock and the driver unit 44 based on a timing signal from the light source unit 34.

  Based on the timing control signal from the readout timing controller 42, the driver unit 44 is illuminated with the illumination light emitted from the light source unit unit 34 as described above according to the rate converted video signal therefrom. By driving the spatial modulation element 46 as a device, a projection image is obtained. This projected image is projected onto a screen (not shown) by a projection optical system (not shown).

  As shown in FIG. 1B, the readout timing controller 42 performs phase synchronization processing in the PLL circuit 48 on the timing signals from the motor drive control circuit 22 and the light emission timing control circuit 24 of the light source unit 34. A frame memory read clock having a frequency multiplied by a predetermined value with respect to the timing signal is generated. The frame memory read clock is uniquely determined by the display resolution of the spatial modulation element 46. Therefore, the video signal read from the frame memories 40R, 40G, and 40B is signal rate converted so as to be synchronized with the phase timing signal from the light source unit 34 and match the resolution of the spatial modulation element 46 to be displayed. Will be made.

  The timing control signal supplied from the read timing controller 42 to the driver unit 44 includes a video synchronization signal (frame signal) and a driver timing control signal. Here, the video synchronization signal (frame signal) is also a PLL in the read timing controller 42 in response to the timing signals from the motor drive control circuit 22 and the light emission timing control circuit 24 of the light source unit 34, similarly to the frame memory read clock. A phase synchronization process is performed in the circuit 48 to obtain a frequency multiplied by a predetermined value with respect to the timing signal. A driver timing control signal for instructing the operation timing of the driver unit 44 is generated by the driver control circuit 50 in the read timing controller 42 based on the frame memory read clock.

  Note that the timing signal from the motor drive control circuit 22 in FIG. 1B is a phase timing pulse that is output every time the light guide rod member 12 rotates in one cycle unit of the circle in which the LEDs 18 are arranged. The timing signal from the light emission timing control circuit 24 is a phase timing pulse output for each color group in which the plurality of LEDs 18 are arranged and for each distance between the LEDs 18. These phase timing pulses can be selectively switched by using a timing selection circuit 52 in the readout timing controller 42 in FIG.

  In the light emission timing control circuit 24, rotation detection / color group information from the rotation sensor 20 is input to the PLL circuit 54 and the light emission timing generation circuit 56. The PLL circuit 54 generates a reference clock synchronized with the rotation of the light guide rod member 12 based on the input rotation detection / color group information and supplies it to the light emission timing generation circuit 56. The light emission timing generation circuit 56 compensates for the deviation between the position of the light inlet 12I of the light guide rod member 12 and the lighting position of the LED 18 from the input reference clock and rotation detection / color group information. A signal and a lighting switching clock are generated.

  In the present embodiment, the drive LED selection circuit 26 and each LED drive circuit 28 shown in FIG. 3 are actually provided with a plurality of sequential lighting circuits 58 (series A sequential lighting as shown in FIG. 1B). Circuit 58A to series D sequential lighting circuit 58D). Seven or eight LEDs 18 are connected to the drive lines of each series, the LEDs 18 of series A and B, and the LEDs 18 of series C and D are alternately arranged, so that a total of 31 LEDs 18 are circular and have a light emitting surface. It is arranged toward the inside of the circle. Also, the LEDs 18 of the same series are alternately arranged so as not to line up such as A-1, B-1, A-2, B-2,. The light inlets 12I of the T-shaped light guide rod member 12 arranged inside the LEDs 18 arranged in this way each have a width corresponding to two LEDs. The series A sequential lighting circuit 58A to the series D sequential lighting circuit 58D are configured so that, in accordance with the lighting switching clock from the light emission timing generation circuit 56, the LEDs 18 of each series are sequentially turned on one by one, and a total of four LEDs 18 are simultaneously turned on. The LED 18 to be lit is switched.

  According to the image projection apparatus according to the present embodiment having the above-described configuration, an image such as a start-up time or jitter can be improved by improving the rotation speed on the light source unit 34 side and the control method for making the light emission control follow the input video data. The response time until the image is stabilized when the signal phase fluctuates can be shortened.

  The projection image can be easily corrected by reducing temporal and positional fluctuations of surface unevenness due to individual light amount variations of the LEDs 18, and the correction result is a uniform image with little unevenness and less flicker that is temporal unevenness. An image is obtained.

  In addition, when the light source is composed of a plurality of LEDs 18 having different colors, color reproducibility is deteriorated by synchronizing so that the phase of the video data and the phase of the emission color do not shift when the phase of the input video data fluctuates. There is nothing to do.

[Second Embodiment]
The read timing controller 42 may be configured as shown in FIG. That is, a read clock having a predetermined period generated by the read clock generator 60 is supplied to the frame memories 40R, 40G, and 40B as the frame memory read clock via the forced reset circuit 62, and the horizontal / vertical synchronization of the input video data is performed. A signal is supplied to the driver unit 44 as the synchronization signal via the forced reset circuit 62. Further, the read clock from the read clock generator 60 is supplied to the driver control circuit 50 through the forced reset circuit 62, and a driver timing control signal to the driver unit 44 is generated.

  In the present embodiment, the forced reset circuit 62 forcibly resets the frame memory read clock, the synchronization signal, and the driver timing control signal from the driver control circuit 50 in accordance with the timing signal from the light emission timing generation circuit 56. Thus, the frame timing of the image information modulated by the spatial modulation element 46 is controlled in synchronization with the relative movement timing of the plurality of LEDs 18 and the light guide rod member 12.

[Third Embodiment]
As shown in FIG. 2A, the image projection apparatus according to the present embodiment detects the amount of illumination light emitted from the exit end face 120 of the light guide rod member 12, that is, the exit end face of the tapered rod 12C. A detection sensor 64 is provided.

  FIG. 5 is a diagram showing the configuration of the light source unit 34 in the present embodiment, in which a light amount correction circuit due to variation in the amount of illumination light is added to the configuration of the light source unit 34 shown in FIG. .

  That is, the light amount variation correction data generation circuit 66 generates correction data for each color of the LED 18 from the light amount monitor signal that is the detection result of the light amount detection sensor 64, and the generated correction data is stored in the ROM 68 as the light amount variation storage means. Write to. This operation is performed when the power of the image projection apparatus is turned on. One LED 18 is lit separately for each color to detect the amount of change in illumination light amount for each color. As a result, correction data for each color is generated, and different address settings are received from the light emission timing generation circuit 56 according to the LED 18 for each color, and are written in the ROM 68. The ROM 68 is configured by, for example, an electrically rewritable EEPROM.

  The ROM 68 receives different address settings from the light emission timing generation circuit 56 according to the LEDs 18 of the respective colors, and outputs the correction data written in the different addresses as described above to the D / D of the LED drive current control circuit 30. The data is output to the A conversion circuit 70. The D / A conversion circuit 70 outputs the correction data to the current control circuit 72 of the LED drive current control circuit 30 as an analog control voltage. The current control circuit 72 receives the control voltage from the D / A conversion circuit 70, switches the control current of the LED 18 in synchronization with the emission color switching, and controls the light amount by switching the light amount for each emission color. .

  Here, the light amount is controlled by switching the light amount for each emission color. However, the light amount fluctuation of each LED 18 is detected and written in the ROM 68 in advance, and the light amount is controlled by switching the light amount for each LED 18. Anyway.

[Fourth Embodiment]
As shown in FIG. 6, the image projection apparatus according to the present embodiment causes the digital signal processing unit 38 to include the spatial modulation element 46 in a period in which the spatial modulation element 46 modulates input image information in units of frames. A video data correction circuit 74 is further provided as correction control means for correcting and controlling image information used when the spatial modulation element 46 is modulated based on fluctuations in the amount of illumination light.

  That is, the video data correction circuit 74 corrects the rate conversion image signal output from the read timing controller 42 based on the correction data in the ROM 68 written from the light quantity fluctuation correction data generation circuit 66, and the driver unit 44. To supply.

[Fifth Embodiment]
In the first to fourth embodiments, illumination light of three colors of R, G, and B is obtained by one light source unit 34. However, in the present embodiment, a separate light source unit for each emission color. One spatial modulation element 46 is illuminated with illumination light from the unit.

  That is, as shown in FIG. 7, the image projection apparatus according to the present embodiment has three light source unit portions 34R, 34G, and 34B in which a plurality of single color LEDs 18 of R, G, and B are arranged on the circumference. It has. In this case, the relative movement timing of the plurality of LEDs 18 and the light guide rod member 12 synchronized by the readout timing controller is every distance between the LEDs 18 arranged on the circumference. That is, when the light source units 34R, 34G, and 34B are configured for each emission color in this way, the distance information between the LEDs 18 is equivalently used by detecting the timing of one rotation of the light guide rod member 12. The video data and the light emission phase can be matched up to the fine phase during one rotation.

[Sixth Embodiment]
The ROM 68 of the light source unit 34 stores light source information, which is condition information regarding illumination light emitted from the light source unit 34, and supplies the stored light source information to the read timing controller 42 on the main body side. Thus, the above-described control may be performed using the light source information.

  As shown in FIG. 8, the light source information can include a light amount fluctuation amount of the light source unit 34, color information, LED arrangement position information for each color, a relative movement amount, light amount information of the light source unit 34, and the like. . Here, the light amount fluctuation amount of the light source unit 34 is information regarding the light amount of the illumination light emitted by each LED 18. The color information is color information of illumination light that can be emitted by the light source unit 34, and the LED arrangement position information for each color is information related to the arrangement position of the LED 18 for each color. The relative movement amount is a relative movement between the plurality of LEDs 18 and the light guide rod member 12 used when the readout timing controller 42 controls the frame timing of image information modulated by the spatial modulation element 46. This is information about the quantity (that is, the position where the phase timing pulse is emitted). The light amount information of the light source unit 34 is information regarding the amount of illumination light that can be emitted by the light source unit 34.

  With such a configuration, the light source unit 34 can be attached to and detached from the main body, and such light source information is written in the ROM 68 in advance in each light source unit 34. Even when the unit 34 is replaced, the detection and setting change steps can be omitted and the unit 34 can be used immediately.

  The light source information is not limited to the configuration written in the ROM 68 of the light source unit unit 34. For example, the light source information is configured as a contact that can read several patterns of on / off information. A method is also conceivable in which the read timing controller 42 reads data based on the on / off information when it is mounted.

[Seventh Embodiment]
The image projection apparatus according to the present embodiment uses DMD (trademark) as the spatial modulation element 46.

  In the case where a device that performs PWM control of video data such as DMD (trademark) is used as the spatial modulation element 46, the spatial light distribution peak position of the LED 18 and the light guide rod member 12 even if there is no variation in the light emission amount of the individual LEDs. Unevenness occurs due to the relationship between the pulsation pattern of the amount of emitted light due to the passage of and the on / off operation phase of PWM.

  That is, as shown in FIG. 9, light emitting pulses are sequentially given to the LEDs 18 in synchronization with the vertical synchronizing signal to sequentially emit light, and the light guide rod member 12 transmits light from the individual LEDs that emit light. The amount of light emitted as illumination light can be obtained by rotating and condensing so as to drive, but even if there is no variation in individual LED light emission, the spatial light distribution peak position of the LED 18 is guided to the light guide rod. The light emission pattern has a pulsation that maximizes the light amount when the member 12 passes, and the average light emission amount as shown by the broken line is the effective illumination light amount. At that time, the case where control data for continuously reflecting (turning on) the LED light emission intervals for three LEDs as shown in FIG. 9CASE1 is given to DMD (trademark) as CASE1 and CASE1 as shown in CASE2. Even when the ON time is equivalent, when the control data that is divided into two parts and reflected is given, the ON period is the same, but the amount of light emission as described above is the same. Since there is a pulsation, the amount of reflected light is determined by interval integration as in interval 1 and interval 2, so that a level difference occurs between CASE1 and CASE2.

  Therefore, when such a DMD (trademark) is used as the spatial modulation element 46, such unevenness due to PWM control is corrected, and control using the read timing controller 42 as in the above embodiment is performed. It will be necessary. Therefore, in the present embodiment, as indicated by CASE 3, a control for shortening the ON section by a section corresponding to the amount of light of the level difference predicted to be generated, that is, light emission phase correction is performed.

  Specifically, the video data correction circuit 74 in FIG. 6 performs DMD (based on the variation in the amount of illumination light that illuminates the spatial modulation element 46 during the period in which the spatial modulation element 46 modulates input frame-unit image information. (Trademark) is used as correction control means for correcting and controlling the modulation method. In other words, the video data correction circuit 74 stores in advance the basic pattern of the pulsation and information on how much the level is increased or decreased by turning on / off the pulsation. Then, the ROM 68 is referred to determine how much level correction should be performed, and based on the information stored in advance, the pulse width of the PWM control of the DMD (trademark), which is the spatial modulation element 46, is turned on. / Determine the off period.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

  For example, if the image projection apparatus of the present invention is applied to a component for projecting an image in a photographic exposure apparatus, a color copying machine, a color printer, a rewritable electronic paper recording apparatus, etc., an effective image because color adjustment is easy. It can be a forming means.

(Appendix)
The invention having the following configuration can be extracted from the specific embodiment.

(1) An image projection apparatus for projecting an image according to input image information in frame units,
A plurality of LED light sources configured as an integral unit for emitting illumination light are arranged on the circumference, and a light source unit unit that sequentially lights each LED light source in time series,
A spatial modulation element that is modulated in accordance with input frame-unit image information;
Illumination optical means for illuminating the spatial modulation element by guiding the illumination light emitted by the light source unit,
Timing control means for controlling the frame timing of image information modulated by the spatial modulation element;
Comprising
The illumination optical means includes light guide means (light guide rod member) that is synchronized with the lighting timing of the plurality of LED light sources and moves relative to the plurality of LED light sources, so that the time series In order to guide the illumination light emitted by the LED light source sequentially turned on to the spatial modulation element,
The timing control means controls the frame timing of image information modulated by the spatial modulation element in synchronization with the relative movement timing of the plurality of LED light sources and the light guiding means. apparatus.

  This configuration corresponds to FIGS. 1A to 9.

  That is, according to the image projecting device described in (1), in the image projecting device such as a projector using the light source unit unit, the control for causing the rotation speed on the light source unit side and the light emission control to follow the input video signal data. By improving the system, it is possible to shorten the response time until the image is stabilized when the phase of the video signal fluctuates, such as startup or jitter.

  The projection image can be easily corrected by reducing the temporal and positional fluctuations of the surface unevenness due to the variation in individual light quantity of the LED, and the correction result is a uniform image with little unevenness and the flicker that is the temporal unevenness is small. An image is obtained.

  In addition, when the LED light source is composed of a plurality of LEDs having different colors, color reproducibility can be obtained by synchronizing the phase of the video signal data and the phase of the emission color when the phase of the input video signal fluctuates. No longer deteriorates.

(2) The plurality of LED light sources are composed of a plurality of LEDs having different illumination light colors, and LEDs having the same illumination light color are arranged adjacent to each other,
The relative movement timing of the plurality of LED light sources and the light guide unit synchronized by the timing control unit is every one round unit of a circle in which the plurality of LED light sources are arranged on the circumference. The image projector according to (1).

  This configuration corresponds to FIGS. 1A to 9.

(3) The timing control means performs the control using a PLL circuit.
The PLL circuit outputs a phase timing pulse that is output every time the plurality of LED light sources and the light guiding unit move relative to each other of a circle in which the plurality of LED light sources are arranged on the circumference. On the other hand, the image projection apparatus according to (2), wherein the phase of the frame timing of the image information modulated by the spatial modulation element is locked.

  This configuration corresponds to FIG.

(4) The plurality of LED light sources are composed of a plurality of LEDs having different colors of emitted illumination light, and LEDs having the same color of emitted illumination light are arranged adjacent to each other as a group,
The relative movement timing of the plurality of LED light sources and the light guide unit synchronized by the timing control unit is a group unit on a circumference where the plurality of LED light sources are arranged (1). ).

  This configuration corresponds to FIGS. 1A to 6, 8, and 9.

(5) The timing control means performs the control using a PLL circuit.
The PLL circuit outputs a phase timing each time the plurality of LED light sources and the light guiding means move relative to each other by the length of a group on the circumference where the plurality of LED light sources are arranged on the circumference. The image projection apparatus according to (4), wherein the phase of the frame timing of the image information modulated by the spatial modulation element is locked with respect to the pulse.

  This configuration corresponds to FIGS. 1A to 3, 4 to 6, 8 and 9.

(6) The plurality of LED light sources are composed of a plurality of LEDs having a single color of emitted illumination light,
The relative movement timing of the plurality of LED light sources and the light guide unit synchronized by the timing control unit is each distance between the LED light sources arranged on the circumference (1). ).

  This configuration corresponds to FIG.

  (7) Correcting the amount of illumination light emitted from the plurality of LED light sources based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during a period in which the spatial modulation element modulates input frame-unit image information The image projection apparatus according to (1), further comprising correction control means for controlling.

  This configuration corresponds to FIGS. 5 to 9.

  (8) Correcting image information used when modulating the spatial modulation element based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during a period in which the spatial modulation element modulates input frame-unit image information The image projection apparatus according to (1), further comprising correction control means for controlling.

  This configuration corresponds to FIG.

(9) The spatial modulation element is a digital micromirror device (DMD),
Correction control means for correcting and controlling the modulation method of the digital micromirror device based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during a period in which the spatial modulation element modulates input frame-unit image information The image projector according to (1), further comprising:

  This configuration corresponds to FIG. 6 and FIG.

(10) It further includes a light amount sensor for detecting a variation amount of the illumination light amount for illuminating the spatial modulation element,
The image projection apparatus according to any one of (7) to (9), wherein the timing control unit performs the control using a variation amount of the illumination light amount detected by the light amount sensor.

  This configuration corresponds to FIG. 2B and FIGS.

(11) further comprising a light amount variation storage means for storing a variation amount of the illumination light amount detected by the light amount sensor;
The timing control unit performs the control using the stored variation amount of the illumination light amount when the variation amount of the illumination light amount is stored in the light amount variation storage unit. Image projector.

  This configuration corresponds to FIGS. 5 to 9.

  (12) The illumination light amount variation stored in the light amount variation storage means is a value rewritten by the illumination light amount variation detected by the light amount sensor when the apparatus is turned on. The image projecting device according to (11).

  This configuration corresponds to FIGS. 5 to 9.

(13) It further comprises condition information storage means for storing condition information regarding illumination light emitted by the light source unit,
The image projection apparatus according to (1), wherein the timing control unit performs the control using the condition information stored in the condition storage unit.

  This configuration corresponds to FIG.

  (14) The image projection apparatus according to (13), wherein the condition information is information related to a light amount of illumination light emitted from each LED light source (that is, a light amount fluctuation amount of the light source unit).

  This configuration corresponds to FIG.

  (15) The image projection apparatus according to (13), wherein the condition information is color information of illumination light that can be emitted by the light source unit and information regarding an arrangement position of the LED light source for each color.

  This configuration corresponds to FIG.

  (16) The condition information includes a relative amount of movement between the plurality of LED light sources and the light guide means used when the timing control means controls the frame timing of the image information modulated by the spatial modulation element (that is, The image projection apparatus according to (13), which is information relating to a position at which a phase timing pulse is emitted.

  This configuration corresponds to FIG.

  (17) The image projector according to (13), wherein the condition information is information relating to a quantity of illumination light that can be emitted by the light source unit.

  This configuration corresponds to FIG.

(A) is a figure which shows the whole structure of the image projector which concerns on 1st Embodiment of this invention, (B) is a video signal based on the timing signal from the light source unit part in the image projector which concerns on 1st Embodiment. It is a figure which shows the detail of a structure of the light source unit part and read-out timing controller for demonstrating a processing method. (A) is a figure which shows the structure of the light source unit part in the image projector which concerns on 1st Embodiment, (B) is the arrow AA sectional view taken on the line of (A). It is a block diagram which shows the electrical structure of a light source unit part. It is a figure which shows the detail of a structure of a light source unit part and a read-out timing controller for demonstrating the video signal processing method based on the timing signal from the light source unit part in the image projector which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the light source unit part in the image projector which concerns on 3rd Embodiment of this invention. It is a figure which shows the detail of a structure of a light source unit part and a read-out timing controller for demonstrating the video signal processing method based on the timing signal from the light source unit part in the image projector which concerns on 4th Embodiment of this invention. It is a figure which shows the structure of the image projector which concerns on 5th Embodiment of this invention. It is a figure which shows the structure of the image projector which concerns on 6th Embodiment of this invention. It is a wave form diagram which shows the fluctuation | variation of the emitted light amount of the light source, and the phase fluctuation | variation of an input video signal in the image projector which concerns on 7th Embodiment of this invention. It is a wave form diagram which shows the fluctuation | variation of the emitted light amount of the light source in the image projector assumed by this invention, and the phase fluctuation | variation of an input video signal. It is a wave form diagram which shows the fluctuation | variation of the illumination light quantity in a projection image by the phase fluctuation | variation of an input video signal.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... Rod holder, 12 ... Light guide rod member, 12A ... Parallel rod, 12B ... Reflective prism, 12C ... Tapered rod, 12I ... Light inlet, 12O ... Output end face, 14 ... Rotation motor, 16 ... LED board, 18 ... LED 20 Rotation sensor 22 Motor drive control circuit 24 Light emission timing control circuit 26 LED selection circuit 28 LED drive circuit 30 LED drive current control circuit 32 Heat sink 34 34R 34G , 34B ... light source unit, 36 ... video front end, 38 ... digital signal processor, 40R, 40G, 40B ... frame memory, 42 ... timing controller, 44 ... driver, 46 ... spatial modulation element, 48,54 ... PLL circuit 50 ... Driver control circuit 52 ... Timein 56: Light emission timing generation circuit, 58: Sequential lighting circuit, 58A ... Series A sequential lighting circuit, 58B ... Series B sequential lighting circuit, 58C ... Series C sequential lighting circuit, 58D ... Series D sequential lighting circuit, 60 ... Read clock generator 62 ... Forced reset circuit 64 ... Light quantity detection sensor 66 ... Light quantity fluctuation correction data generation circuit 68 ... ROM 70 ... D / A conversion circuit 72 ... Current control circuit 74 ... Video data correction circuit .

Claims (17)

An image projection device that projects an image according to image information in units of input frames,
A plurality of LED light sources configured as an integral unit for emitting illumination light are arranged on the circumference, and a light source unit unit that sequentially lights each LED light source in time series,
A spatial modulation element that is modulated in accordance with input frame-unit image information;
Illumination optical means for illuminating the spatial modulation element by guiding the illumination light emitted by the light source unit,
Timing control means for controlling the frame timing of image information modulated by the spatial modulation element;
Comprising
The illumination optical means includes LED light sources that are synchronized with the lighting timings of the plurality of LED light sources and that move relative to the plurality of LED light sources, so that the LED light sources sequentially light in time series. Is directed to the spatial modulation element.
The timing control means controls the frame timing of image information modulated by the spatial modulation element in synchronization with the relative movement timing of the plurality of LED light sources and the light guiding means. apparatus. The plurality of LED light sources are composed of a plurality of LEDs having different illumination light colors, and LEDs having the same illumination light color are arranged adjacent to each other.
The relative movement timing of the plurality of LED light sources and the light guide unit synchronized by the timing control unit is every one round unit of a circle in which the plurality of LED light sources are arranged on the circumference. The image projection apparatus according to claim 1. The timing control means performs the control using a PLL circuit,
The PLL circuit outputs a phase timing pulse that is output every time the plurality of LED light sources and the light guiding unit move relative to each other of a circle in which the plurality of LED light sources are arranged on the circumference. On the other hand, the phase of the frame timing of the image information modulated by the spatial modulation element is locked. The plurality of LED light sources are composed of a plurality of LEDs having different illumination light colors, and LEDs having the same illumination light color are arranged adjacent to each other as a group.
The relative movement timing of the plurality of LED light sources and the light guide unit synchronized by the timing control unit is each group unit on a circumference where the plurality of LED light sources are arranged. 2. The image projection apparatus according to 1. The timing control means performs the control using a PLL circuit,
The PLL circuit outputs a phase timing each time the plurality of LED light sources and the light guiding means move relative to each other by the length of a group on the circumference where the plurality of LED light sources are arranged on the circumference. 5. The image projection apparatus according to claim 4, wherein a phase of a frame timing of image information modulated by the spatial modulation element is locked with respect to a pulse. The plurality of LED light sources are composed of a plurality of LEDs having a single color of emitted illumination light,
The relative movement timing of the plurality of LED light sources and the light guide means synchronized by the timing control means is every distance between the LED light sources arranged on the circumference. 2. The image projection apparatus according to 1.   Correction for correcting and controlling the amount of illumination light emitted from the plurality of LED light sources based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during a period in which the spatial modulation element modulates input image information in units of frames The image projection apparatus according to claim 1, further comprising a control unit.   Correction for correcting and controlling image information used for modulating the spatial modulation element based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during the period in which the spatial modulation element modulates input frame-unit image information The image projection apparatus according to claim 1, further comprising a control unit. The spatial modulation element is a digital micromirror device,
Correction control means for correcting and controlling the modulation method of the digital micromirror device based on fluctuations in the amount of illumination light that illuminates the spatial modulation element during a period in which the spatial modulation element modulates input frame-unit image information The image projector according to claim 1, further comprising: A light amount sensor for detecting a variation in the amount of illumination light that illuminates the spatial modulation element;
The image projection apparatus according to claim 7, wherein the timing control unit performs the control using a variation amount of the illumination light amount detected by the light amount sensor. A light amount variation storage means for storing a variation amount of the illumination light amount detected by the light amount sensor;
The said timing control means performs the said control using the variation | change_quantity of the illumination light quantity memorize | stored when the variation | change_quantity of illumination light quantity is memorize | stored in the said light quantity fluctuation | variation storage means. Image projector.   The illumination light quantity fluctuation amount stored in the light quantity fluctuation storage means is a value rewritten by the illumination light quantity fluctuation amount detected by the light quantity sensor when the apparatus is turned on. The image projection device according to 11. Further comprising condition information storage means for storing condition information relating to the illumination light emitted by the light source unit,
The image projection apparatus according to claim 1, wherein the timing control unit performs the control using the condition information stored in the condition storage unit.   The image projection apparatus according to claim 13, wherein the condition information is information related to a light amount of illumination light emitted from each LED light source.   The image projection apparatus according to claim 13, wherein the condition information is color information of illumination light that can be emitted by the light source unit and information regarding an arrangement position of the LED light source for each color.   The condition information is information relating to a relative amount of movement between the plurality of LED light sources and the light guide means used when the timing control means controls the frame timing of image information modulated by the spatial modulation element. The image projection apparatus according to claim 13.   The image projection apparatus according to claim 13, wherein the condition information is information related to a quantity of illumination light that can be emitted by the light source unit.

Images