JP5286884B2 - Projector, projector control program, and light source control method - Google Patents

Description

  The present invention relates to a projector that performs projection using a plurality of light sources having different emission colors, a control program for the projector, and a light source control method.

  2. Description of the Related Art Conventionally, projectors that use three LEDs that emit RGB colors as light sources instead of halogen lamps have been proposed in order to reduce the size and portability of devices. However, when three LEDs that emit RGB colors are used as the light source in this way, the LEDs of each color are sequentially turned on, and only one of the LEDs of RGB is instantaneously turned on instantaneously. , And the brightness of the LED is much inferior to that of the halogen lamp, and thus the projected image cannot be made bright.

Therefore, at the timing of lighting an LED of a certain color, the LEDs of other colors are driven and lit at a low output, for example, the LED of G color and B color is turned on at the timing of lighting an R color LED. Projectors have also been proposed in which the brightness of the projected image can be ensured by turning on at low output (see, for example, Patent Document 1).
JP 2004-317558 A

  However, when the LED is driven at a current value lower than the rated value, the light emission color changes according to the drive current value, and the LED emits light in a color different from the original light emission color of the LED. Accordingly, as described above, for example, when the G and B LEDs are turned on at a low output at the timing of turning on the R color LED, the light emission color in which the G color and the B color are added to the R color as a whole. Instead, an unexpected light emission color is obtained by adding a G change color in which the G color is changed and a B change color in which the B color is changed to the R color.

  For this reason, although the merit that high brightness can be secured in the projected image is obtained, the demerit that the chromaticity adjustment of the projected image becomes difficult occurs.

  The present invention has been made in view of such a conventional problem, and even when an LED is used as a light source, a projector capable of achieving both the luminance securing and chromaticity adjustment of a projected image, and the projector. It is an object to provide a control program and a light source control method.

  In order to solve the above-mentioned problem, the invention described in claim 1 is to turn on a plurality of light sources having different emission colors in a time-division manner within one frame projection time, and a predetermined number of floors for each time-division lighting of each light source. A projector that projects an image in a tone, and includes a control unit that pulses a light source of another light emission color at a predetermined constant interval during time-division lighting of the light source of one light emission color among the plurality of light sources. It is characterized by that.

  According to the present invention, even when an LED is used as a light source, it is possible to ensure brightness in the projected image and adjust the chromaticity of the projected image.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing an electrical configuration of a projector 1 common to the embodiments of the present invention. The projector 1 includes a control unit 11, an input / output interface 12, an image conversion unit 13, a display encoder 14, a display drive unit 15, and the like. The image data is converted by the image conversion unit 13 so as to be unified into an image signal of a predetermined format suitable for display via the input / output interface 12 and the system bus 17 and then sent to the display encoder 14.

  The display encoder 14 develops and stores the transmitted image signal in the video RAM 18, generates a video signal from the stored contents of the video RAM 18, and outputs the video signal to the display driving unit 15.

  The display drive unit 15 to which a video signal is input from the display encoder 14 drives a DMD 19 (digital micromirror device) as a display element at every 256 gradations at an appropriate frame rate corresponding to the transmitted video signal. To do. The light beam emitted from the light source device 20 is incident on the DMD 19 via the light source side optical system, thereby forming an optical image with the reflected light of the DMD 19 and via the movable lens group 21 serving as the projection side optical system. The image is projected and displayed on a screen (not shown). The movable lens group 21 of the projection side optical system is driven by a lens motor 22 for zoom adjustment and focus adjustment.

  The image compression / decompression unit 23 performs recording processing for compressing the luminance signal and the color difference signal in the image signal by processing such as ADTC and Huffman coding, and writing the data onto a memory card 24 that is a detachable recording medium. Read the image data recorded in the. Individual image data constituting a series of moving images is expanded in units of one frame and sent to the display encoder 14 via the image conversion unit 13 so that moving images and the like can be displayed based on the image data stored in the memory card 24. To do.

  The control unit 11 controls the operation of each circuit in the projector 1, and includes a CPU and its peripheral circuits, a ROM 111, a RAM 112, and the like. The ROM 111 stores programs such as various settings, programs and data shown by flowcharts described later, and the RAM 112 is used as a work memory or the like.

  The key / indicator unit 25 includes a main key and an indicator provided in the main body case and the like, and an operation signal thereof is sent to the control unit 11. The key operation signal from the remote controller is received by the Ir receiver 26, demodulated by the Ir processor 27, and the code signal is sent to the controller 11.

  The light source device 20 includes a red LED 20R that emits an R (red) color, a green LED 20G that emits a G (green) color, and a blue LED 20B that emits a B (blue) color. The control unit 11 controls the light source control circuit 32 to perform time-division control on the LEDs 20R, 20G, and 20B in accordance with the image signal, and pulse control as described later.

  The ROM 111 stores a pulse lighting width initial value pattern PP for one frame shown in FIG. 2 together with the program and the like. This pulse lighting width initial value pattern PP corresponds to the time-division lighting of each LED 20R, 20G, 20B in one frame, and the lighting timing at which other LEDs other than time-division lighting are pulse-lit at regular intervals and The pulse width is stored. Further, as for the lighting timing of the LEDs other than the time-division lighting, the higher the frequency, the more appropriate the chromaticity when the image is revealed by the DMD 19, but in this embodiment, 0 to 255. It is assumed that the timing corresponds to the gradation operation.

  In other words, when the other LEDs described above are pulsed for a predetermined amount of light as will be described later, the chromaticity balance during the lighting period is made appropriate by lighting the pulse as frequently as possible by shortening the pulse width. However, since the DMD 19 which is the display element in this embodiment reflects the light emitted from the light source device 20 based on the 0 to 255 gradations as described above and creates an image, at least the 0 to 255 An appropriate chromaticity balance can be obtained by adjusting the light incident on the DMD 19 at the timing of each gradation by turning on other LEDs as described above.

  That is, within one frame, the pulse width for driving the green LED and the blue LED at 256 gradation timings is stored while the red LED is turned on in a time-division manner, and during the time when the green LED is turned on in a time-division manner. The pulse width for driving the red LED and the blue LED at 256 gradation timings is stored, and the pulse width for driving the red LED and the green LED at 256 gradation timings during the time division lighting of the blue LED is stored. Is remembered.

  The pulse lighting width initial value pattern PP has a pulse width that can increase the luminance to some extent and does not substantially affect the chromaticity.

  In the present embodiment having the above configuration, the control unit 11 of the projector 1 executes processing according to the flowchart shown in FIG. 3 based on the program stored in the ROM 111. That is, the pulse lighting width initial value pattern PP is read from the ROM 111 and set in a predetermined area of the RAM 112 (step SA1). Next, it is determined whether or not a display mode is set (step SA2).

  Here, the display mode is a display mode other than the normal mode in which the light source device 20 is driven using the pulse lighting width initial value pattern PP, for example, a brightness enhancement mode for enhancing the brightness of the projected image, and the brightness is ignored. Faithful reproduction mode that emphasizes faithful reproduction of the original color of the image, red enhancement mode that emphasizes the red, green, and blue of the projected image, or makes the projected image generally red, green, and bluish , Green enhancement mode, blue enhancement mode, and the like.

  If the result of determination in step SA2 is that the display mode has not been set while still in the normal mode, the process proceeds to step SA5 without executing steps SA2 to SA4, and the preset pulse An image is projected while driving the light source device 20 with the lighting width initial value pattern PP. Therefore, in this case, the RAM 112 remains in the state where the pulse lighting width initial value pattern PP is set.

  However, if one of the display modes is set as a result of the determination in step SA2, a pulse lighting width pattern is created according to the set mode (step SA3).

  Creation of the pulse lighting width pattern is executed according to a subroutine shown in FIG. That is, by determining the G and B lighting width pulse in the time division lighting of the red LED and arranging the pulses having the determined pulse width corresponding to the 0 to 255 gradations, the green LED in the time division lighting of the red LED. A blue LED lighting width pulse pattern is created (step S1). Therefore, a pulse lighting width pattern corresponding to the portion (1) in FIG. 2 is created by the processing in step S1.

  Subsequently, similarly, a red LED and blue LED lighting width pulse pattern in time division lighting of the green LED is created (step S2), and a red LED and green LED lighting width pulse pattern in blue LED time division lighting is created. (Step S3). Therefore, the pulse lighting width pattern corresponding to the (2) portion and (3) portion in FIG. 2 is created by the processing in step S2 and step S3.

  And the pulse lighting width pattern which consists of (1) (2) (3) part in FIG. 2 will be completed by connecting the pulse lighting width pattern produced by these steps S1-S3 (step S4).

  In this way, the pulse lighting width pattern may be created independently without using the lighting width initial value pattern PP. However, if the pulse lighting width pattern is created by using the lighting width initial value pattern PP and correcting it, Can be created efficiently.

  That is, in the case where the lighting width initial value pattern PP is used and the faithful reproduction mode is set in step SA2, for example, when the R, G, B color LEDs are used in the lighting width initial value pattern PP. If the lighting pulses of the other LEDs at the time of division lighting are attenuated or eliminated, the R, G, B color LEDs are only time-division lighting, and the original color of the image can be reproduced faithfully.

  Also, for example, when the green enhancement mode is set to enhance the green color or to make the projected image have a greenish color overall, the pulse widths of the red LED and the blue LED when the green LED is time-divisionally lit are set. Narrow (or no pulse “0”), widen the pulse width of the green LED during time-division lighting of the red LED, and narrow the blue LED pulse width (or “0” without the pulse), and time-division of the blue LED The pulse width of the green LED at the time of lighting may be widened and the pulse width of the red LED may be narrowed (or no pulse “0”).

  Then, the pulse lighting width pattern created based on the display mode selected in step SA2 is overwritten and set in a predetermined area of the RAM 112 (step SA4).

Thereafter, image projection is performed while driving the light source device 20 with the set pulse lighting width pattern (step SA5). That is, if the lighting width initial value pattern PP shown in FIG. 2 is set in a predetermined area of the RAM 112, the R, G, and B color LEDs 20R, 20G, and 20B are turned on in a time-division manner in one frame,
(1) During time-division lighting of the red LED 20R, the green LED 20G and the blue LED 20B are lit and driven at a timing corresponding to 0 to 255 gradations with the illustrated pulse width,
(2) During time-division lighting of the green LED 20G, the red LED 20R and the blue LED 20B are lit and driven at a timing corresponding to the 0 to 255 gradations with the illustrated pulse width,
(3) During time-division lighting of the blue LED 20B, the red LED 20R and the green LED 20G are driven to light at a timing corresponding to 0 to 255 gradations with the illustrated pulse width.

At this time,
[1] During time-division lighting of the red LED 20R, the auxiliary-lit green LED 20G and the blue LED 20B are pulse-driven, and therefore can be controlled only by turning the LED on and off without changing the LED current value. The emission color of each LED that is pulse-lit does not change, the light from the green LED 20G is the original green, and the light from the blue LED 20B is the original blue.
[2] During time-division lighting of the green LED 20G, the auxiliary-lit red LED 20R and blue LED 20B are pulse-driven, and therefore can be controlled only by turning the LED on and off without changing the LED current value. The emission color of each LED that is pulse-lit does not change, the light from the red LED 20R is the original red, and the light from the blue LED 20B is the original blue.
[3] When the blue LED 20B is turned on in a time-sharing manner, the red LED 20R and the green LED 20G that are lit in an auxiliary manner are pulse-driven, so that the LED current value is not changed and the control can be performed only by turning the LED on and off. The emission color of each LED that is pulse-lit does not change, the light from the red LED 20R is the original red, and the light from the green LED 20G is the original green.

  In this way, the auxiliary lighted LED does not have a different emission color from the original color, and only the amount of emission of the color increases according to the pulse width. Therefore, not only can the brightness be ensured in the projection image in accordance with the pulse width applied to the auxiliary lit LED, but also the projection image is changed by changing the pulse width in the above-described steps SA2 and SA3. It is also possible to freely adjust the chromaticity.

  In addition, according to the present embodiment, not only can the brightness be ensured in the projection image but also the chromaticity of the projection image can be freely adjusted according to a desired display mode arbitrarily set by the user. It is also possible.

(Second Embodiment)
In the second embodiment of the present invention, as shown in FIG. 5, the ROM 111 further stores a waveform data table WT. The waveform data table WT stores the sync signal waveform corresponding to various standard names of image data input from the input / output connector section 16 such as “analog RGB”.

  FIG. 6 is a flowchart showing a processing procedure in the second embodiment. That is, the lighting width initial value pattern PP is read from the ROM 111 and set in a predetermined area of the RAM 112 (step SB1). Next, a human power signal supplied from the personal computer or the like to the input / output connector unit 16 at a frame rate according to the standard of the image data, or image data read from the memory card 24 at a frame rate according to the standard The presence or absence of input signals sequentially input is determined (step SB2).

  If the result of determination in step SB2 is that there is an input signal, the sync signal waveform in the input signal is compared with the sync signal waveform stored in the waveform data table WT (step SB3). Further, it is determined whether or not the standard of the input signal has been found as a result of this comparison (step SB4).

  If the standard of the input signal is not found, the process proceeds to step SB7 without executing the processes of steps SB5 and SB6. Therefore, if the standard of the input signal is not found, the lighting width initial value pattern PP remains set in the RAM 112.

  However, if the standard of the input signal is found as a result of the determination in step SB4, a pulse lighting width pattern is created in accordance with the found standard of the input signal (step SB5). The pulse lighting width pattern may be created in accordance with the subroutine of FIG. 4 described above, or may be created by using the lighting width initial value pattern PP and correcting it.

  Alternatively, the pulse lighting width pattern may be stored in the waveform data table WT of FIG. 5 corresponding to various standard names, and this may be simply read out. In this way, a pulse lighting width pattern according to the standard of the input signal can be obtained by easy processing.

  Then, the pulse lighting width pattern created in this way is overwritten and set in a predetermined area of the RAM 112 (step SB6). Thereafter, as in the first embodiment described above, image projection is executed while driving the light source device 20 with the set pulse lighting width pattern (step SB7).

  That is, the input signal may have a chromaticity range that can be displayed in advance depending on the standard. In other words, since the maximum values of R, G, and B in the chromaticity diagram may be determined in advance by the standard of the input signal, the light source device is in the time-division lighting state of each of the red LED 20R, the green LED 20G, and the blue LED 20B. The pulse lighting width is determined so that the emission color at becomes the maximum value of R, G, B in the chromaticity diagram. Therefore, according to the second embodiment, it is possible to appropriately ensure the luminance of the projected image and appropriately adjust the chromaticity of the projected image according to the standard of the input signal. .

(Third embodiment)
FIG. 7 is a flowchart showing a processing procedure in the third embodiment of the present invention. That is, the lighting width initial value pattern PP is read from the ROM 111 and set in a predetermined area of the RAM 112 (step SC1). Next, it is determined whether image data supplied from a personal computer or the like or image data read from the memory card 24 has been input to the input / output connector unit 16 (step SC2). If image data is input, it is A / D converted (step SC3), and RGB digital data in the A / D converted image data is stored in the RAM 112 (step SC4).

  Subsequently, the maximum values of R, G, and B in the image are detected based on the RGB digital data stored in the RAM 112 (step SC5). That is, the value of each vertex of R, G, B of the color triangle in the chromaticity diagram is detected. Then, a pulse lighting width pattern is created based on the detected maximum values of R, G, and B (step SC6). That is, in the chromaticity diagram, while obtaining a color triangle whose vertex is the maximum value of R, G, B of the image data, RGB which is each vertex of the color triangle which is a displayable area of the LEDs 20R, 20G, 20B The pulse lighting width is determined so that the primary color matches each vertex of the color triangle of the image data, and a pulse lighting width pattern is created.

  The pulse lighting width pattern created in this way is overwritten and set in a predetermined area of the RAM 112 (step SC7). Thereafter, as in the first embodiment described above, image projection is performed while driving the light source device 20 with the set pulse lighting width pattern (step SC8).

  Therefore, according to the third embodiment, it is possible to appropriately ensure the brightness of the projected image and appropriately adjust the chromaticity of the projected image according to the color characteristics of the input image data. Is also possible.

  In the third embodiment, every time image data is input (step SC2; YES), the maximum values of R, G, and B in the image are detected (step SC5), and based on this. A pulse lighting width pattern is created (step SC6), and the light source device 20 is driven. Therefore, when image data having greatly different maximum values of R, G, and B are sequentially input, a significantly different pulse lighting width pattern is created each time, and the light source device 20 is driven. A phenomenon occurs in which the degree changes rapidly. Therefore, when the change width of the maximum values of R, G, and B exceeds a predetermined value, the maximum value may be regulated to a lower value. As a result, it is possible to suppress the occurrence of a phenomenon in which the luminance and chromaticity of the image change abruptly.

  In particular, in the case of a moving image, since different image data is input for each frame, image data having different maximum values of R, G, and B is likely to be input. Is likely to change rapidly. Therefore, for example, a pulse lighting width pattern is created based on the average value of the maximum values of R, G, and B in a plurality of frames so that the brightness and chromaticity of the image do not change suddenly. It is preferable to create the pulse lighting width pattern while adjusting the maximum values of R, G, and B.

  In the above-described embodiment, one frame is time-divided into three, and the red LED 20R, the green LED 20G, and the blue LED 20B are lit in a time-division manner. However, as shown in FIG. You may make it time-divide into pieces. In this case, as shown in the figure, the fourth time division timing is assigned to white (W), and at the time of white time division lighting, the red LED 20R, the green LED 20G, and the blue LED 20B are all pulse-driven every 0 to 255 gradations. Alternatively, as shown in the figure, the LED of the color most desired to be used when white is generated may be caused to emit all light (in this example, “G”), and the other LEDs may be pulse-driven.

  As described above, when using the pulse lighting width pattern in which all of the red LED 20R, the green LED 20G, and the blue LED 20B are pulse-driven at the time of white time-division lighting, it is possible to more appropriately ensure the luminance in the projected image and The degree can be fine-tuned. Further, when the color LED that is most desired to be used for generating white light is made to emit all light and the other LEDs are pulse-driven, white can be projected with a favorite color.

  Further, in the above-described embodiment, the other LEDs are configured to be pulse-lit every 256 gradations. However, the present invention is not limited to this, and may be pulse-lit more frequently or conversely. The pulse may be turned on with. In any case, it suffices if it is configured to light up at regular intervals during the pulse lighting period. At that time, the chromaticity can be adjusted by changing the pulse width for pulse lighting.

  In the above-described embodiments, LEDs having different emission colors are used as light sources, but a plurality of light sources having different emission colors other than LEDs may be used.

1 is a block diagram showing a circuit configuration of a projector according to an embodiment of the present invention. It is a schematic diagram which shows an example of a pulse lighting width initial value pattern. It is a flowchart which shows the process sequence in the 1st Embodiment of this invention. It is a flowchart which shows the procedure of a pulse lighting width pattern creation process. It is a schematic diagram which shows a waveform data table. It is a flowchart which shows the process sequence in the 2nd Embodiment of this invention. It is a flowchart which shows the process sequence in the 3rd Embodiment of this invention. It is a schematic diagram which shows an example of the pulse lighting width pattern when one frame is divided into four times.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projector 11 Control part 12 Input / output interface 13 Image conversion part 14 Display encoder 15 Display drive part 16 Input / output connector part 19 DMD
20 Light source device 20R Red LED
20G green LED
20B Blue LED
24 Memory Card 25 Key / Indicator Unit 26 Ir Receiver 32 Light Source Control Circuit 111 ROM
112 RAM
PP pulse lighting width initial value pattern WT waveform data table

Claims (13)

A projector that lights a plurality of light sources having different emission colors in a time division manner within one frame projection time, and projects an image with a predetermined number of gradations for each time division lighting of each light source,
A projector comprising control means for pulsing light sources of other light emission colors at predetermined constant intervals during time-division lighting of a light source of one light emission color among the plurality of light sources.   The projector according to claim 1, wherein the plurality of light sources having different emission colors are LEDs each emitting red, green, and blue. The control means includes
Creating means for creating a pulse pattern for lighting the light source of the other emission color at the predetermined constant interval;
The projector according to claim 1, further comprising: a driving unit that drives the light source of the other emission color according to the pulse pattern created by the creating unit. Comprising storage means for storing at least one pulse pattern;
4. The projector according to claim 3, wherein the creating unit creates another pulse pattern based on the pulse pattern stored in the storage unit. Comprising mode setting means for selectively setting a plurality of modes;
5. The projector according to claim 3, wherein the creating unit creates different pulse patterns according to the mode set by the mode setting unit. Input means for inputting image data;
Standard detection means for detecting the standard of the image data input from the input means,
5. The projector according to claim 3, wherein the creating unit creates a different pulse pattern according to a standard of the image data detected by the standard detecting unit. Input means for inputting image data;
Component detection means for detecting a predetermined image component in the image data input from the input means,
Said generating means in response to the picture Zo構 formed elements detected by the component detecting means, the projector according to claim 3 or 4, wherein creating a different pulse patterns. The image Zo構 formation element, the projector of claim 7, wherein the is image data of a color triangle formed by R, G, and B each vertex values. The control means, within one frame projection time, to form a time-division lighting time for turning on a plurality of light sources having different emission colors in a time-division manner, and a time-division turning-off time in which none of the light sources is lit in a time-division manner,
The projector according to any one of claims 1 to 8, further comprising means for turning on all the light sources in a pulsed manner for each gradation during the time-division turn-off time.   The projector according to any one of claims 1 to 9, wherein the control unit causes the light sources of the other light emission colors to pulse at regular intervals for each of the predetermined number of gradations.   The projector according to claim 10, wherein the predetermined number of gradations is 256 gradations. A computer having a projector that projects a plurality of light sources having different emission colors in a time-division manner within one frame projection time and projects an image with a predetermined number of gradations for each time-division lighting of each light source,
A projector control program for causing a light source of another light emission color to function as a control unit that performs pulse lighting at a predetermined constant interval during time-division lighting of a light source of one light emission color among the plurality of light sources. A light source control method in a projector that projects a plurality of light sources having different emission colors in a time division manner within one frame projection time, and projects an image with a predetermined number of gradations for each time division lighting of each of the light sources,
A light source control method comprising: pulse-lighting light sources of other light emission colors at predetermined constant intervals during time-division lighting of a light source of one light emission color among the plurality of light sources.

Images