JP2017201834A - Projection device, projection method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform image projection with correct and high image quality constantly by keeping the continuity of color gradation while factoring in the change in a light emission state of a light-emitting element.SOLUTION: A projection device comprises: a light source part 15 operable to use a plurality of kinds of light-emitting elements to circularly emit a plurality of colors of light in a time sharing manner; a micro mirror element 14 operable to use light from the light source part 15 to display an image corresponding to color components thereof, and to form an optical image by its reflection light; a projection lens part 17 operable to project the optical image thus formed toward a projection target; and a digital power source 18 which sets a switching timing of a plurality of colors of light and a spoke period centered on the timing, drives the light source part 15 on the basis of the set switching timing and the set spoke period, detects information showing a light quantity of each color light projected from the projection lens part 17 during the spoke period, and sets a delay time of a light emission timing in the light source part 15 during the spoke period on the basis of the light quantity of each color light thus obtained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projection apparatus, a projection method, and a program that are particularly suitable for a DLP (registered trademark) (Digital Light Processing) type projector.

  In a DLP (registered trademark) projector device using a semiconductor light emitting element such as an LED (light emitting diode) or LD (semiconductor laser) as a light source, the light emission efficiency varies greatly due to thermal fluctuations immediately after the light emission of the element starts and thereafter. Therefore, it is essential to consider the variation in the luminous efficiency in order to improve the quality of the projected image.

  In this regard, for example, by adjusting the brightness of the light emitting elements of each color of the LED array based on supply power waveform information that cancels the luminance fluctuation in each field period for each color component with respect to the LED array, A technique has been considered in which the influence is suppressed and the quality of the projected image is maintained at a high level. (For example, Patent Document 1)

JP 2007-094108 A

  In the above-described type of projector apparatus, it is difficult to switch each color instantaneously at a specific timing, and it is common to have a specification that temporarily provides a period in which a plurality of emission colors are mixed. The switching period in which a plurality of colors are mixed is referred to as a “spoke period” because of the single-plate DLP system developed on the premise of using a color wheel. In the DLP method, it is assumed that this spoke period is used effectively as mixed color light that has been measured in advance.

  However, the semiconductor light emitting element realizes a target current value by using a current control technique such as PID control. However, the rise and fall characteristics of the light emission drive change depending on the applied voltage and temperature, individual differences of the elements, and the like. In addition, the rise and fall characteristics of the light emission drive change depending on individual differences such as capacitor capacity in a circuit including a semiconductor light emitting element, elements such as a low-pass filter, and a driving state.

  When the rising and falling characteristics of the semiconductor light emitting element change, the color as mixed-color light also changes from time to time. Such changes in the characteristics of the rising and falling characteristics of the semiconductor light emitting element cannot be dealt with by the technique described in the above-mentioned patent document. When the actual light emission amount in the spoke period is different from the light emission amount measured in advance, the continuity of the gradation of the projected color is lost and the image quality deteriorates.

The present invention has been made in view of the above circumstances, and its purpose is to maintain the continuity of color gradation in consideration of changes in the light emission state of a semiconductor light emitting element used as a light source. Another object of the present invention is to provide a projection apparatus, a projection method, and a program that can always project with high accuracy and high image quality.

  According to one embodiment of the present invention, a light source unit that cyclically emits light of a plurality of colors by light emission from a plurality of types of light-emitting elements, and an image corresponding to a color component of the light using the light from the light source unit A display element that displays a light image by reflected light or transmitted light, a projection unit that emits a light image formed by the display element toward a projection target, a switching timing of the light of the plurality of colors, and Timing setting means for setting a spoke period centered on the switching timing, light source driving means for driving the light source unit based on the switching timing and the spoke period set by the timing setting means, and the spoken period during the spoke period Based on detection means for detecting information indicating the light quantity for each color light emitted from the projection unit, and information indicating the light quantity for each color light in the previous spoke period obtained by the detection means. Te, characterized by comprising a light source control means for setting a delay time of the light emission timing in the light source unit in the same spoke period after the color image of one frame, a.

  According to the present invention, it is possible to always perform projection with high accuracy and high image quality while considering the change in the light emission state of the light emitting element used for the light source and maintaining the continuity of the color gradation.

1 is a block diagram showing a functional circuit configuration of a projector device according to a first embodiment of the present invention. The block diagram which shows the internal circuit structure of the digital power supply of FIG. 1 which concerns on the embodiment. The timing chart which shows the segment switching pulse which concerns on the same embodiment, the drive state of each light emitting element, and a display image. The figure which shows the electric current value measurement timing of the spoke period which concerns on the same embodiment. The figure which shows the rising characteristic of the spoke period which changes with the individuals which concern on the same embodiment. The figure which shows the example of a setting of delay time Tdl of the spoke period which concerns on the same embodiment. The figure which shows the switching state of the various drive conditions in the spoke period which concerns on the same embodiment. The figure explaining the drive condition of the digital power supply with respect to LED which emits red (R) light based on the embodiment, and the control content.

(First embodiment)
A first embodiment in which the present invention is applied to a DLP (registered trademark) projector device will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a schematic functional configuration of a projector apparatus 10 according to the present embodiment. In the figure, the input unit 11 includes, for example, a pin jack (RCA) type video input terminal, a D-sub 15 type RGB input terminal, an HDMI (registered trademark) (High-Definition Multimedia Interface) terminal, and the like. Various standard analog or digital image signals input to the input unit 11 are digitized by the input unit 11 as necessary, and then sent to the image conversion unit 12 via the system bus SB.

  The image conversion unit 12 is generally also called a scaler or formatter, and sends input digital value image data to a projection processing unit 13 in a unified format with image data suitable for projection.

  At this time, data such as symbols indicating various operation states for OSD (On Screen Display) is also superimposed on the image data by the image conversion unit 12 as necessary, and the processed image data is sent to the projection processing unit 13.

  The projection processing unit 13 multiplies a frame rate according to a predetermined format, for example, 120 [frames / second], the number of color component divisions, and the number of display gradations, in accordance with the transmitted image data. The micromirror element 14 that is a spatial light modulation element is driven to display by the time-division driving.

  This micromirror element 14 is turned on / off individually at a high speed for each inclination angle of a plurality of micromirrors arranged in an array, for example, WXGA (Wide eXtended Graphics Array) (horizontal 1280 pixels × vertical 800 pixels). By displaying the image, an optical image is formed by the reflected light.

  On the other hand, R, G, and B primary color lights are emitted cyclically from the light source unit 15 in a time-sharing manner. The primary color light from the light source unit 15 is totally reflected by the mirror 16 and applied to the micromirror element 14.

  Then, an optical image is formed by the reflected light from the micromirror element 14, and the formed optical image is projected and displayed on a screen (not shown) to be projected via the projection lens unit 17.

  The light source unit 15 includes an LED (light emitting diode) that emits red light, an LD (semiconductor laser) that emits blue laser light for irradiating a phosphor to excite green light, and an LED that emits blue light. To do.

  The projection processing unit 13 controls the formation of an optical image by displaying an image on the micromirror element 14 and the light emission of LEDs and LD as light emitting elements in the light source unit 15 under the control of the CPU 19 described later. On the other hand, a segment switching timing pulse is sent to the digital power supply 18, and a command signal for power supply control is sent to and received from the digital power supply 18.

  The digital power source 18 generates and supplies a large number of DC voltage values necessary for each circuit from the AC power source provided for the projector device 10 and is necessary for driving the LEDs and LDs to the light source unit 15. Supply power.

  FIG. 2 shows a configuration of a portion for driving the light source unit 15 in the digital power source 18. That is, in the digital power supply 18, the voltage applied to the light source unit 15 is adjusted by the voltage adjusting unit 31. In the process in which electric power whose voltage has been adjusted is supplied to a load such as an LED or LD in the light source unit 15, the current measurement unit 32 measures the current value (light source current value). A measurement result in the current measuring unit 32 is fed back to a DSP (Digital Signal Processor) 33. The DSP 33 adjusts the voltage value in the voltage adjusting unit 31 by performing feedback control on the current value flowing in the light emitting element driven at that time by the segment switching timing pulse and the power supply control command given from the projection processing unit 13.

  The CPU 19 controls all the operations of the above circuits. The CPU 19 is directly connected to the main memory 20 and the program memory 21. The main memory 20 is constituted by an SRAM, for example, and functions as a work memory for the CPU 19. The program memory 21 is composed of an electrically rewritable nonvolatile memory, and stores an operation program executed by the CPU 19 and various fixed data. In other words, the CPU 19 uses the main memory 20 and the program memory 21 to execute a control operation in the projector device 10.

The CPU 19 executes various projection operations in accordance with key operation signals from the operation unit 22.
The operation unit 22 includes a key operation unit provided in the main body of the projector device 10 and an infrared light receiving unit that receives infrared light from a remote controller (not shown) dedicated to the projector device 10. A key operation signal based on a key operated by a remote controller or a remote controller is directly output to the CPU 19.

  The CPU 19 is further connected to the audio processing unit 23 via the system bus SB. The sound processing unit 23 includes a sound source circuit such as a PCM sound source, converts the sound data given via the system bus SB during a projection operation into an analog signal, drives the speaker unit 24 to emit a loud sound, or a beep sound if necessary. Is generated.

Next, the operation of the above embodiment will be described.
Note that all of the operations described below indicate processing executed by the DSP 33 in the digital power supply 18 under the control of the CPU 19.

  FIG. 3 shows the segment switching pulse input from the projection processing unit 13 to the digital power source 18 and the timing of the image displayed on the light source unit 15 and the micromirror element 14 that operate in synchronization therewith.

  As shown in FIG. 3A, as the segment switching timing pulse is input from the projection processing unit 13 to the digital power source 18, the R, G, and B segments are switched in synchronization with the rising timing tup of the pulse. Shall.

  More specifically, a fixed time Tsp is set as the spoke period from the rising timing tup of the segment switching timing pulse, and the primary colors R, G, and B are respectively imaged from the end timing of the spoke period Tsp to the next rising timing tup. Is set as the period of each segment to project.

  FIG. 3B to FIG. 3D illustrate waveforms of drive currents of a red light LED, an LD that emits blue light for green excitation by a phosphor, and an LED that emits blue light.

  Here, the digital power source 18 turns off the light emitting element driven in the preceding segment in synchronization with the initial timing tup of the spoke period Tsp, and at the same time, starts light emission of the light emitting element used in the next segment.

  When the light emitting element is turned off, the driving current of each light emitting element is sharply reduced by stopping the driving after a minute waiting time.

  On the other hand, at the start of light emission of the light emitting element, a time lag is generated from the timing tup by a current rising period, and then the current rises with a gentler slope than the slope at which the current value drops when the light is turned off.

  Therefore, in the spoke period Tsp, the light source unit 15 emits light that gradually changes from the previous segment color to the next segment color.

  That is, in the spoke period between the R segment and the G segment, the light emitted from the light source unit 15 gradually changes from red to green. During this spoke period, the projection processing unit 13 causes the micromirror element 14 to display a light image corresponding to yellow (Ye), which is a mixed color of red and green.

  In the spoke period between the next G segment and B segment, the light emitted from the light source unit 15 gradually changes from green to blue. During this spoke period, the projection processing unit 13 causes the micromirror element 14 to display a light image corresponding to cyan (Cy), which is a mixed color of green and blue.

  Furthermore, in the spoke period between the B segment and the R segment, the light emitted from the light source unit 15 gradually changes from blue to red. During this spoke period, the projection processing unit 13 causes the micromirror element 14 to display a light image corresponding to magenta (Mg), which is a mixed color of blue and red.

  On the other hand, in each of the R, G, and B segments, the projection processing unit 13 causes the micromirror element 14 to display a light image corresponding to each primary color as described above.

  FIG. 4 shows the control of the drive current of the semiconductor light emitting element in the light source unit 15 by the digital power source 18 during the spoke period Tsp for an LD that emits blue light to excite green (G) light by a phosphor. The case is shown as an example. The black circles shown in the figure indicate the sampling timing of the LD current value measured by the digital power supply 18. In this way, the digital power supply 18 performs a control to finely measure the current value flowing through the light emitting element to be controlled in the spoke period as well as the segment period, and to feed back to the voltage value to be applied based on the measurement result. ing.

In the spoke period, the digital power source 18 starts applying a voltage to the LD from the start timing tup and measures the value of the flowing current. After the current rise time from the timing tup in relation such forward drop voltage has passed, in which a current value flowing through the LD is gradually increased, the digital supply 18 is its maximum value to maintain the target current i _T in FIG. In the state where the feedback control is executed as described above, the next segment period, here, the G segment is entered.
The current rise time during which the current value does not increase from the timing tup changes including factors such as individual differences of the semiconductor light emitting elements and various driving conditions, and cannot be shortened further.

FIG. 5 illustrates the difference in rise time due to these various factors in terms of the characteristics of two LD individuals that emit blue light to excite green (G) light by the phosphor.
Compared with the rise characteristics of the LD current in the spoke period shown in FIG. 5A, the rise time Δt1 is short, the subsequent rise is steep, and the time until the current value reaches the target current i _T is also short. In the LD current rising characteristic shown in FIG. 5B, the rising time Δt2 is long, the subsequent rising slope is gentle, and the time until the current value reaches the target current i _T is also long.

  When the area of the hatched portion shown in the figure is proportional to the amount of light emission, the LD individual shown in FIG. 5A and the LD individual shown in FIG. The LD individuals shown in (1) clearly have a larger light emission during the spoke period. Therefore, by deliberately delaying the rise time for LD individuals with better rise characteristics, it is possible to achieve the same amount of light emission as LD individuals with inferior rise characteristics. It is possible to correct the display gradation of each color component in consideration of the characteristics and project an image while maintaining the continuity of the gradation of each color component.

With respect to the rectangle formed by the spoke period Tsp and the target current i _T , the measured value of the hatched area ratio is α, the target value of the hatched area ratio is β, and the delay time Tdl is
Tdl = Tsp × (α−β) (1)
Can be expressed as In order to prevent “(α−β)” in the above expression (1) from becoming a negative value, the target value β of the area ratio of the hatched portion is set in advance by experiments so as to be a minimum assumed area.

  By calculating the delay time Tdl by the DSP 33 in the digital power supply 18, the area of the hatched portion in the spoke period Tsp can be made constant, and the light emission amount can be kept constant in consideration of individual differences of the semiconductor light emitting elements. Can do.

  FIG. 6 shows an example of setting such a delay time Tdl. Here, a case where the delay time Tdl is set for the two LDs having the rising characteristics shown in FIG. 5 is shown.

  That is, by setting the delay time Tdl calculated by the above equation (1) for the LD having higher responsiveness in the rising characteristics shown in FIG. 5A, FIG. As shown in FIG. 6, the area of the hatching portion can be made equal to the area of the hatching portion of the LD having the rising characteristics shown in FIG. 6B, and the light emission amount in the spoke period Tsp can be set evenly.

The target value β and the time Tsp of the ratio in the above equation (1) are appropriately set from the maximum value and minimum value of the assumed rise time.
This point is not limited to the rising characteristic of starting light emission in the light emitting element during the spoke period, but the falling characteristic for stopping light emission from the previous segment period in the spoke period and the drive current value of the light emitting element are changed (increased or decreased). In the case of (decrease), the same control can be executed.

FIG. 7 shows the switching state of various drive conditions during such a spoke period. FIG. 7A illustrates the rising characteristics of the current value when light emission is started during the spoke period and the target current i _T is maintained during the next segment period, as described above with reference to FIGS. Thus, the degree of change for each light emitting element is the largest in the case of starting the light emission from the unlit state and raising the flowing current. This is because the range in which the value of the current flowing through the load is increased from the start to the target current value is the largest and has time, and the influence on the gradation expression is large due to the magnitude of the change.

  FIG. 7B illustrates the falling characteristic of the current value when light emission is stopped during the spoke period. When light emission is stopped in this way, the current value decreases to the extinguished state in a very short time from the target current value, so that the rise from the extinguished state as shown in FIGS. 4 to 6 and FIG. Compared to characteristics, the influence of individual differences among light emitting elements is relatively small, but even in this case, gradation expression is influenced by individual differences among light emitting elements.

FIG. 7C illustrates a case where the first target current i _T1 to the second target current i _T2 (i _T1 < The rising characteristic of the current value when increasing the current value up to i _T2 ) is illustrated. In the case of increasing the current while maintaining the light emission in this way, although not as high as the rising characteristic from the light-off state as shown in FIGS. 4 to 6 and FIG. Easy to be influenced by gradation expression.

FIG. 7D illustrates a current value falling characteristic when the current value is decreased from the first target current i _T1 to the second target current i _T2 (i _T1 > i _T2 ) during the spoke period. . In this way, when the current is decreased while maintaining the light emission, the gradation expression due to the individual difference of the light emitting element is more affected than the falling characteristic to the light-off state as shown in FIG. 7B. Easy to receive.

Consider the case where the above equation (1) is further generalized in view of various driving states during the spoke period as described above.
The first current target value that is the current target value before switching is A,
The second current target value, which is the current target value after switching, is B,
The average current measurement during the spoke period is C,
The average current target value for the spoke period is D,
When the time of the spoke period is Tsp, the delay time Tdl is
Tdl = Tsp * (CD) / (BA) (2)
Can be expressed as

  The average current target value D and the time Tsp in the above equation (2) are appropriately set in advance according to the assumed maximum value and minimum value of the average current measurement value C.

  If gradation expression is also a problem in the above formulas (1) and (2) due to the deviation from the continuity between the light emission amount and the current value, the light emission amount (illuminance value) from the current value by an appropriate conversion formula. Then, the above equation (1) or (2) may be used after a predetermined correction is added to the current value based on the light emission amount.

  Further, instead of estimating the light emission amount from the current value to the light emitting element as described above, for example, when an illumination sensor is further provided and the light emission amount (illuminance value) of each light emitting element can be measured, Instead of measuring the value, the light emission amount of each light emitting element may be directly measured.

In that case,
The light emission before switching is A,
The light emission after switching is B,
C,
D for the target light emission amount during the spoke period
The above equation (2) can be used. The light emission amount target value D for the spoke period is obtained by multiplying the light emission amount A before switching and the light emission amount B after switching by a predetermined coefficient using an arithmetic expression prepared in advance. By doing so, it is possible to more accurately grasp the light emission state of each light emitting element and realize a precise gradation expression. Of course, the light emission amount target value D during the spoke period may be obtained through actual experiments.

Next, the timing for executing the above-described control will be described.
The driving conditions of the digital power source 18 for the LED emitting red (R) light in the light source unit 15 and the control contents thereof will be described as an example with reference to FIG.

  When the DSP 33 drives the LED to emit light in the spoke period Tsp immediately before the R segment, the average current value is measured by the current measuring unit 32 (step S01), and the delay time Tdl is calculated using the above equation (1) or (2). Calculate (step S02).

The DSP 33 sets the calculated delay time Tdl (step S03), drives the LED to emit light with the newly set delay time Tdl in the spoke period Tsp immediately before the R segment of the next image frame, and again averages the current. The process of measuring the value by the current measuring unit 32 is repeatedly executed. ,
In this way, by reflecting the measurement result in the spoke period in the same spoke period of the next image frame, it is possible to immediately cope with the variation in the driving state of the light emitting element and maintain the gradation expression of the projected image in good condition.

  The above-described control is started, for example, when the power is turned on, when a predetermined continuous operation time (ex. 10 minutes, 30 minutes, 60 minutes, etc.) has elapsed, or when the projection mode (ex. Presentation mode, theater mode, etc.) is switched. Then, after being repeatedly performed a predetermined number of times, it may be temporarily stopped and then waited until the above-described control is performed. Further, for example, it may be performed continuously from the start of image projection to the end of image projection.

  In the above embodiment, for the sake of simplification of description, for example, an LD that emits blue light and an LED that emits red (R) light to excite green (G) light by a phosphor have been described. The DSP 33 in the digital power source 18 that controls the driving state of the light source unit 15 in the projector device 10 measures the driving state of individual light emitting elements that emit light in total of two colors or, if necessary, three colors that emit light during the spoke period. Thus, the light emission amount for each color is adjusted in consideration of the balance for each color. Therefore, in each segment period of the primary color lights R, G, and B, gradation control is performed so that the color balance in the entire image frame is not lost depending on the degree of color mixture (complementary color) adjusted in the spoke period. Therefore, correct gradation expression utilizing the control of the spoke period can be realized.

  As described above, in the present embodiment, the delay time is set so that each color light emitted from the projection lens unit has a desired light emission amount. Therefore, considering the change in the light emission state of the light emitting element used for the light source, Image projection that maintains continuity of color gradation is possible.

  As described above in detail, according to the present embodiment, it is possible to always project with high accuracy and high image quality while maintaining the continuity of the color gradation in consideration of the change in the light emission state of the light emitting element used for the light source. It becomes.

  Furthermore, in the above embodiment, the start timing of the light emitting element of the color that starts light emission during the spoke period is delayed by the control of the light source unit 15 of the digital power supply 18, but this has an effect on the gradation expression. The continuity of the color gradation can be reliably maintained in consideration of the rising characteristics of the light-emitting elements that are easily received.

  On the other hand, the control of delaying the end timing of the light emitting element of the color that starts light emission during the spoke period makes it possible to continue color gradation without reducing the light emission amount in the spoke period. It can also be controlled to maintain sex.

  In the above embodiment, the light emitting element in the light source unit 15 is configured by a semiconductor light emitting element such as an LD or an LED. By using such a semiconductor light emitting element, precise control can be easily realized by utilizing the high-speed response of the digital power supply 18.

  In the above embodiment, the digital power source 18 samples the drive current of each light emitting element of the light source unit 15 and calculates and sets the delay time of the light emission timing during the spoke period from the sampled drive current waveform of each light emitting element. Therefore, precise control can be easily realized by utilizing the high-speed response as the digital power supply 18.

(Second Embodiment)
A second embodiment in which the present invention is applied to a DLP projector device will be described below with reference to the drawings.

  The schematic functional configuration of the projector apparatus 10 'according to the present embodiment is the same as that shown in FIG. 1, and the configuration of the portion that drives the light source unit 15 in the digital power source 18 in the projector apparatus 10' is the above. The contents shown in FIG. 2 are basically the same as those shown in FIG. 2, and the same reference numerals are used for the same parts, and illustration and description thereof are omitted.

Next, the operation of the above embodiment will be described.
Note that all of the operations described below indicate processing executed by the DSP 33 in the digital power supply 18 under the control of the CPU 19.

  Under the condition that the voltage value adjusted by the voltage adjusting unit 31 in the digital power supply 18 is constant, the gradation expression is greatly affected when the target current value is greatly different. When a semiconductor light emitting element such as an LD or LED is used, since the control amount of the light emission amount is relatively large, in order to switch the brightness as the projector device 10 ′, it is necessary to largely change the supplied current value.

  In the case where it is only necessary to prevent the change in color and light emission amount during the spoke period due to the change in the current value, it is possible to realize control that is greatly simplified as compared with the method described in the first embodiment.

That is, an appropriate delay time is examined in association with several drive current values assumed for each light emitting element, and stored in the DSP 33 as a lookup table, or an arithmetic expression is stored.
The stored contents stored in the DSP 33 in this way may be stored as representative values depending on the individual difference of each light emitting element, or may be stored individually. An appropriate delay time Tdl is acquired and set from the stored contents and the measurement result of the current value actually passed through the light emitting element. As specific prediction methods for setting the delay time Tdl, two methods will be described below.

<First prediction method: linear interpolation>
In the first method, the delay time Tdl is set by performing interpolation such as linear interpolation from the current value and the measurement result of the current value by the current measuring unit 32. That is,
A suitable delay time for current A is B,
D for the appropriate delay time at current C,
Let E be the current value of the light source to be set, and the delay time Tdl
Tdl = B + (D-B) * (EA) / (CA) (3)
And As described above, by calculating the delay time Tdl by the calculation according to the equation (3), it is possible to maintain the color expression and the light emission amount of the spoke period Tsp constant and to maintain the gradation expression correctly.

<Second prediction method: step interpolation>
In the second method, several current value ranges and stepwise delay times are associated with each other and stored in the DSP 33 in the form of a lookup table or an arithmetic expression, and associated with the range to which the actual current value belongs. Get and set the stored delay time.

  Setting the stepwise delay time in this way is effective when the drive current value fluctuates greatly due to, for example, switching of the operation mode accompanied by increase / decrease in the light emission amount of each light emitting element.

  Regardless of which of the above two methods is employed, it is possible to always project with high accuracy and high image quality while maintaining the continuity of color gradation in consideration of changes in the light emission state of the light emitting element used as the light source. In addition, the control load on the DSP 33 in the digital power supply 18 can be greatly reduced as compared with the first embodiment, and the configuration of the digital power supply 18 can be further simplified.

  In the first and second embodiments, the light source unit 15 of the projector device 10 (10 ′) directly emits red (R) light and blue (B) light from the LED and emits green (G) light. Although the case where the phosphor is obtained by exciting the phosphor with the blue light emitted from the LD has been described, the present invention does not limit the type or number of light emitting elements serving as the light source.

  In addition to the above embodiment, for example, after measuring the light emission amounts of the R, G, and B color lights in the entire spoke period of one color image frame, for example, the total light emission amount in the three spoke periods Tsp is obtained. A constant to be expressed may be calculated by calculation, and the delay time of the light emission timing in the light source unit during each spoke period may be set collectively based on this constant. This setting is such that the total light emission amount of the color light projected during a plurality of spoke periods in one frame of the color image becomes a desired light emission amount.

  In this manner, the display tone of the color component is corrected in consideration of the falling characteristics and the rising characteristics in each spoke period, and the total color balance in the three spoke periods Tsp is appropriate through one color image frame. Such control is executed. Furthermore, since the delay of the light emission timing is set for each frame of the color image, the load on the CPU 19 can be reduced compared to the above embodiment.

  In the above embodiment, the delay time of the light emission timing during the spoke period is calculated from the sampled drive current waveform of each light emitting element. However, the present invention is not limited to this, and the drive power waveform or drive voltage waveform of each light emitting element is used. The delay time of the light emission timing during the spoke period may be calculated.

  In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the functions executed in the above-described embodiments may be combined as appropriate as possible. The above-described embodiment includes various stages, and various inventions can be extracted by an appropriate combination of a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the effect is obtained, a configuration from which the constituent requirements are deleted can be extracted as an invention.

Hereinafter, the invention described in the scope of claims of the present application will be appended.
According to the first aspect of the present invention, a light source unit that cyclically emits light of a plurality of colors by light emission from a plurality of types of light emitting elements and light from the light source unit are used, and the color component of the light is supported. A display element that displays an image and forms a light image by reflected or transmitted light; a projection unit that emits a light image formed by the display element toward a projection target; and a switching timing of the light of the plurality of colors. And a timing setting means for setting a spoke period centered on the switching timing, a light source driving means for driving the light source unit based on the switching timing and the spoke period set by the timing setting means, and during the spoke period Based on detection means for detecting information indicating the amount of light for each color light emitted from the projection unit, and information indicating the amount of light for each color light obtained by the detection means, the light source driver Characterized in that due to and a light source control means for setting a delay time of the light emission timing in the light source unit in said spoke period.

  According to a second aspect of the invention, in the first aspect of the invention, the light source control means sets the delay time so that each color light emitted from the projection unit has a desired light emission amount. Features.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the timing setting means sets a plurality of spoke periods in one color image frame, and the light source control means has one color image frame. The delay time is set so that a total light emission amount of each color light projected from the projection unit during a plurality of spoke periods has a desired light emission amount.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the detection unit samples a driving current waveform, a driving voltage waveform, or a driving power waveform of each light emitting element by the light source driving unit. The light source control means calculates and sets a delay time of the light emission timing in the light source unit during the spoke period from the drive current waveform, drive voltage waveform, or drive power waveform of each light emitting element sampled by the detection means. It is characterized by doing.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, further comprising storage means for storing in advance the drive power of each light emitting element and the delay time of the light emission timing during the spoke period. The light source control means reads and sets the delay time of the light emission timing from the storage means based on the detection result of the detection means.

  The invention according to claim 6 is the invention according to any one of claims 1 to 4, wherein the detection means measures an illuminance value for each color light emitted from the light source unit, and the light source control means A delay time of light emission timing in the light source unit during the spoke period is calculated and set from the illuminance value obtained by the detecting means.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the light source control means sets a delay time at the start of light emission in the light source section during a spoke period by the light source driving means. It is characterized by that.

  The invention according to claim 8 is the invention according to any one of claims 1 to 6, wherein the light source control means sets a delay time at the end of light emission in the light source unit during a spoke period by the light source driving means. It is characterized by that.

  According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the light emitting element of the light source unit uses at least one of a semiconductor laser and a light emitting diode.

  According to a tenth aspect of the present invention, in the invention according to any one of the first to ninth aspects, the light source control means uses the same spoke after one frame of the color image based on the detection result in the spoke period obtained by the detection means. A delay time of light emission timing in the light source unit is set in a period.

  According to an eleventh aspect of the present invention, there is provided a light source unit that cyclically emits light of a plurality of colors by light emission from a plurality of types of light emitting elements, and an image corresponding to a color component of the light using light from the light source unit. A display element that displays a light image by reflected light or transmitted light, and a projection method in an apparatus including a projection unit that emits a light image formed by the display element toward a projection target, A timing setting step for setting the switching timing of the light of the plurality of colors and a spoke period centered on the switching timing, and a light source for driving the light source unit based on the switching timing and the spoke period set in the timing setting step A driving process; a detecting means for detecting information indicating a light quantity for each color light emitted from the projection unit during the spoke period; and a light quantity for each color light obtained by the detecting means. Based on the information, characterized in that and a light source control step of setting a delay time of the light emission timing in the light source unit in said spoke period in the light source driving step.

  The invention according to claim 12 is a light source unit that cyclically emits light of a plurality of colors by light emission of a plurality of types of light emitting elements, and uses light from the light source unit, and an image corresponding to a color component of the light A program executed by a computer built in a display element that displays a light image by using the reflected light or transmitted light and a projection unit that emits the light image formed by the display element toward a projection target The computer is configured based on the switching timing and the spoke period set by the timing setting means, the timing setting means for setting the switching timing of the light of the plurality of colors, and the spoke period centered on the switching timing. A light source driving means for driving the light source unit, and a detector for detecting information indicating the light quantity of each color light emitted from the projection unit during the spoke period And based on the information indicating the light quantity for each color light obtained by the detection means, the light source drive means functions as a light source control means for setting a delay time of the light emission timing in the light source unit during the spoke period. It is characterized by that.

DESCRIPTION OF SYMBOLS 10,10 '... Projector apparatus, 11 ... Input part, 12 ... Image conversion part, 13 ... Projection process part, 14 ... Micromirror element, 15 ... Light source part, 16 ... Mirror, 17 ... Projection lens part, 18 ... Digital power supply 19 ... CPU, 20 ... main memory, 21 ... program memory, 22 ... operation unit, 23 ... audio processing unit, 24 ... speaker unit, 31 ... voltage adjustment unit, 32 ... current measurement unit, 33 ... DSP (Digital Signal Processor) ), SB ... System bus.

One embodiment of the present invention is formed on the basis of an input image signal using a light source unit that cyclically emits light of a plurality of colors in a time-division manner by light emission of a plurality of types of light-emitting elements, and light from the light source unit. a projection unit for morphism exiting the light image was based on the information indicating the quantity of each color light emitted from the projection unit in front of the spoke period around the switching timing of the plurality of colors of light, And a light source control means for setting a delay time of the light emission timing in the light source section in the same spoke period one frame after the color image.

Claims (11)

A light source unit that cyclically emits light of a plurality of colors in a time division manner by light emission of a plurality of types of light emitting elements;
A display element for displaying an image corresponding to a color component of the light using the light from the light source unit and forming a light image by the reflected light or transmitted light;
A projection unit for emitting a light image formed by the display element toward a projection target;
Timing setting means for setting the switching timing of the light of the plurality of colors, and a spoke period centered on the switching timing,
Light source driving means for driving the light source unit based on the switching timing and the spoke period set by the timing setting means;
Detecting means for detecting information indicating a light amount for each color light emitted from the projection unit during the spoke period;
Light source control means for setting a delay time of the light emission timing in the light source section in the same spoke period one frame after the color image based on information indicating the light quantity for each color light in the previous spoke period obtained by the detection means A projection apparatus comprising:   The projection apparatus according to claim 1, wherein the light source control unit sets the delay time so that each color light emitted from the projection unit has a desired light emission amount. The timing setting means sets a plurality of spoke periods in one color image frame,
The light source control means sets the delay time so that a total light emission amount of each color light projected from the projection unit during a plurality of spoke periods of one frame of a color image becomes a desired light emission amount. The projection apparatus according to claim 1 or 2. The detecting means samples a driving current waveform, a driving voltage waveform, or a driving power waveform of each light emitting element by the light source driving means,
The light source control means calculates and sets a delay time of the light emission timing in the light source unit during the spoke period from the drive current waveform, drive voltage waveform, or drive power waveform of each light emitting element sampled by the detection means. The projection apparatus according to claim 1, wherein the projection apparatus is a projection apparatus. It further comprises storage means for storing in advance the driving power of each light emitting element and the delay time of the light emission timing during the spoke period,
5. The projection apparatus according to claim 1, wherein the light source control unit reads and sets a delay time of light emission timing from the storage unit based on a detection result of the detection unit. The detection means measures an illuminance value for each color light emitted from the light source unit,
5. The light source control means calculates and sets a delay time of light emission timing in the light source unit during the spoke period from the illuminance value obtained by the detection means. Projection device.   The projection apparatus according to claim 1, wherein the light source control unit sets a delay time at the start of light emission in the light source unit during a spoke period by the light source driving unit.   7. The projection apparatus according to claim 1, wherein the light source control unit sets a delay time at the end of light emission in the light source unit during a spoke period by the light source driving unit.   9. The projection apparatus according to claim 1, wherein the light emitting element of the light source unit uses at least one of a semiconductor laser and a light emitting diode. A light source unit that emits light of a plurality of colors in a time-division manner by light emission of a plurality of types of light-emitting elements, using light from the light source unit, displaying an image corresponding to the color component of the light, and reflecting light or A projection method in an apparatus including a display element that forms a light image with transmitted light, and a projection unit that emits a light image formed by the display element toward a projection target,
A timing setting step for setting the switching timing of the light of the plurality of colors, and a spoke period centered on the switching timing;
A light source driving step of driving the light source unit based on the switching timing and the spoke period set in the timing setting step;
A detection step of detecting information indicating a light amount for each color light emitted from the projection unit during the spoke period;
A light source control step for setting a delay time of the light emission timing in the light source unit in the same spoke period one frame after the color image based on information indicating the light quantity for each color light in the previous spoke period obtained in the detection step When,
A projection method characterized by comprising: A light source unit that emits light of a plurality of colors in a time-division manner by light emission of a plurality of types of light-emitting elements, using light from the light source unit, displaying an image corresponding to the color component of the light, and reflecting light or A program executed by a computer built in a display element that forms a light image with transmitted light, and a device that includes a projection unit that emits a light image formed by the display element toward a projection target,
The computer
Timing setting means for setting the switching timing of the light of the plurality of colors, and a spoke period centered on the switching timing,
Light source driving means for driving the light source unit based on the switching timing and the spoke period set by the timing setting means;
Based on detection means for detecting information indicating the light quantity for each color light emitted from the projection unit during the spoke period, and information indicating the light quantity for each color light in the previous spoke period obtained by the detection means. A program that functions as light source control means for setting a delay time of light emission timing in the light source unit in the same spoke period after one frame of a color image.

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