Projection device, projection method, and program

Abstract

To provide an image projection device which reduces loss of light source energy.SOLUTION: An image projection device 10 provided herein comprises a light source drive unit 17 configured to control a light source unit 18 to emit light of a third color different from first and second colors according to a first signal for the first color and a second signal for the second color different from the first color.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a projection device, a projection method, and a program. [Background technology]

[0002] A commercially available projector has a high-speed rotating color wheel (or phosphor wheel) placed between the projector's light source unit and a micromirror element called a DMD (Digital Micromirror Device), and the light source unit emits primary color light consisting of, for example, red (R), green (G), and blue (B) light in a time-division manner toward the DMD by switching the output of each light source ON / OFF at the timing of the segment switch (the middle timing of the spoke period) in the color wheel.The projection processing unit that controls the DMD outputs light source pulses to instruct the output of each light source to be switched ON / OFF at the timing of the segment switch (the middle timing of the spoke period) in the color wheel.

[0003] This light source pulse is output in the middle of the spoke period, not at the start of the spoke period. This creates a period in which the two colors of light mix. This mixed light can cause degradation of image quality, and if it is discarded unused, it will result in a loss of light source energy (loss of brightness). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-81819 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a projection device, a projection method, and a program that effectively control the output timing of light output from a light source unit. [Means for solving the problem]

[0006] A projection device according to one aspect of the present invention includes a light source driver that controls a light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color. the light source driving unit outputs a light emission signal that rises at a start timing of a spoke period, which is a period for switching the color of light and in which a composite signal generated based on the first signal and the second signal is in a high level state and is in a high level state at the start timing of the spoke period, and is in a low level state at the end timing of the spoke period, and controls the light source unit to emit light of the third color based on the output light emission signal. do. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a projection device, a projection method, and a program that reduce loss of light source energy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a projection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of the light source unit shown in FIG. [Figure 3] FIG. 3 is a plan view of the phosphor wheel shown in FIG. [Figure 4] FIG. 4 is a block diagram of the projection processing unit and the light source driving unit shown in FIG. [Figure 5] FIG. 5 is a timing chart illustrating the light source switching operation of the projection device according to the comparative example. [Figure 6] FIG. 6 is a timing chart illustrating the light source switching operation of the projection device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions, ratios, etc. of each drawing are not necessarily the same as those in reality. The several embodiments shown below are examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not specified by the shape, structure, arrangement, etc. of the components. In the following description, elements having the same function and configuration are designated by the same reference numerals, and duplicated explanations will be omitted.

[0010] [1] Configuration of the projection device 10 1 is a block diagram of a projection device 10 according to an embodiment of the present invention. The projection device 10 is configured as a projector that complies with the DLP (registered trademark) (Digital Light Processing) system, for example.

[0011] The projection device 10 includes an input / output connector 11, an input / output interface (I / F) 12, a bus 13, an image conversion unit 14, a VRAM (Video RAM) 15, a projection processing unit 16, a light source driving unit 17, a light source unit 18, a micromirror element (also called a display element) 19, a mirror 20, a projection lens unit 21, an audio processing unit 22, a speaker 23, a CPU (Central Processing Unit) 24, a memory unit 25, an operation unit 26, and a power supply circuit 27.

[0012] The input / output interface 12, the image conversion unit 14, the VRAM 15, the projection processing unit 16, the audio processing unit 22, and the CPU 24 are connected via a bus 13 so as to be able to send and receive data to and from each other.

[0013] The input / output connector 11 is a terminal for inputting image data to be projected by the projection device 10 from an external device. The input / output connector 11 is realized by, for example, an HDMI (registered trademark) (High-Definition Multimedia Interface) terminal, a pin jack (RCA) type video input terminal, a D-sub 15 type RGB input terminal, a USB (Universal Serial Bus) connector, etc. Furthermore, removable media such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory that stores programs, image data, etc., is appropriately attached to the input / output connector 11.

[0014] A program read from the removable medium via the input / output connector 11 is stored in the storage unit 25 as needed. The removable medium can also store various data stored in the storage unit 25 in the same way as the storage unit 25.

[0015] Image data that conforms to various standards and is input to the input / output connector 11 is sent to the image conversion unit 14 via the input / output interface 12 and bus 13 .

[0016] The image conversion unit 14 converts the image data sent from the input / output connector 11 into an image signal in a predetermined format suitable for projection. The image conversion unit 14 also sends the converted image signal to the projection processing unit 16.

[0017] The VRAM 15 is a buffer memory for image processing, and is used as a buffer when an image signal is transmitted from the image conversion unit 14 to the projection processing unit 16.

[0018] The projection processing unit 16 drives the micromirror element 19 in accordance with the image signal transmitted from the image conversion unit 14 using time-division driving that is a multiplication of a frame rate conforming to a predetermined format, the number of divisions of the color components, and the number of display gradations.

[0019] The micromirror element 19 is a spatial light modulation element that is driven under the control of the projection processing unit 16. The micromirror element 19 has a plurality of micromirrors that respectively correspond to a plurality of pixels arranged in an array (for example, 1024 horizontal pixels by 768 vertical pixels corresponding to XGA). The micromirror element 19 switches the tilt angle of each of the plurality of micromirrors on and off at high speed. When the micromirrors are on, the micromirror element 19 forms an optical image corresponding to an image signal by the reflected light that is emitted to the projection lens unit 21.

[0020] The light source unit 18 cyclically emits light of multiple colors (including the primary colors R (red), G (green), and B (blue)) in a time-division manner. The light of multiple colors from the light source unit 18 is totally reflected by the mirror 20 and irradiated onto the micromirror element 19.

[0021] The projection processing unit 16 adjusts the color to correspond to the color components of the input image signal by adjusting the time that the micromirror element 19 is on for a predetermined period determined for each of the multiple colors of light incident on the micromirror element 19. Then, an optical image is formed by the light reflected by the micromirror element 19, and the formed optical image is projected and displayed via the projection lens unit 21 onto a screen (not shown) that is the projection target.

[0022] The light source driving unit 17 controls the light emission timing and light emission intensity of the semiconductor lasers and LEDs included in the light source unit 18, as well as the rotation of the phosphor wheel driven by the motor, based on the timing signal in the image signal sent from the projection processing unit 16, the index signal input from the index sensor, brightness information input from an optical sensor (not shown), etc. The control by the light source driving unit 17 is performed under the overall control of the CPU 24.

[0023] The audio processing unit 22 includes a sound source circuit such as a PCM (Pulse Code Modulation) sound source, etc. The audio processing unit 22 converts audio data transmitted from the CPU 24 during projection operation into analog data and drives the speaker 23 to emit amplified sound.

[0024] The storage unit 25 includes a ROM (Read Only Memory) as a nonvolatile memory and a RAM (Random Access Memory) as a volatile memory. The ROM stores various programs and various data. The ROM also stores the drive current values ​​of the LEDs and semiconductor lasers when emitting R, G, and B as rated current values ​​when the white balance is achieved at the time of factory shipment. The RAM is used as a work memory for the CPU 24.

[0025] The CPU 24 comprehensively controls the operation of each of the above circuits. The CPU 24 is also called a control unit. The CPU 24 executes various processes based on programs stored in ROM or programs loaded into RAM from removable media. The RAM stores data necessary for the CPU 24 to execute various processes.

[0026] The CPU 24 executes various adjustment operations for the projection operation in response to an operation signal, which is a signal based on a key operation received by the operation unit 26 from the user.

[0027] The operation unit 26 includes a key operation unit provided on the main body of the projection device 10 and a laser light receiving unit that receives infrared light between the key operation unit and a remote controller (not shown) dedicated to the projection device 10. The operation unit 26 transmits to the CPU 24 an operation signal based on a key operation input by the user to the key operation unit of the main body or the remote controller.

[0028] The operation unit 26, together with the key operation unit and the remote controller, includes, for example, a focus adjustment key, a zoom adjustment key, an input switching key, a menu key, a cursor key, a set key, and a cancel key.

[0029] The power supply circuit 27 uses an externally supplied power source to generate various voltages required for the operation of multiple circuits included in the projection device 10. The power supply circuit 27 supplies the generated voltages to the corresponding circuits. The power supply circuit 27 includes a battery. When the supply of external power is stopped, the power supply circuit 27 generates various voltages using the battery and supplies them to the corresponding circuits.

[0030] [1-1] Configuration of light source unit 18 Fig. 2 is a block diagram of the light source unit 18 shown in Fig. 1. The light source unit 18 includes a semiconductor laser 31 for emitting B light, an LED 32 for emitting R light, a mirror 33, a dichroic mirror 34, a phosphor wheel 35, an index sensor 36, a motor (M) 37, a mirror 38, a mirror 39, a dichroic mirror 40, an integrator 41, and a mirror 42. The semiconductor laser 31 is also called a laser diode (LD).

[0031] The light source unit 18 includes two types of light-emitting elements (light sources). That is, the light source unit 18 includes a semiconductor laser 31 that emits blue laser light (also referred to as blue light) and an LED 32 that emits red light. In Fig. 2, the letters R, G, and B and the arrows indicate the color of light (either R, G, or B) and the traveling direction of the light.

[0032] The blue laser light emitted by the semiconductor laser 31 is totally reflected by a mirror 33, passes through a dichroic mirror , and is irradiated onto a part of the circumference of a phosphor wheel .

[0033] The phosphor wheel 35 is made of an annular member and is connected to the rotation shaft of the motor 37. The phosphor wheel 35 is rotated at a constant speed by the motor 37. The phosphor wheel 35, onto which the laser light is irradiated, has a transmissive region that transmits the light and a reflective region that reflects the light on its circumference. The transmissive region of the phosphor wheel 35 functions as a diffuser that diffuses the light. The reflective region of the phosphor wheel 35 is coated with fluorescent paint, and this reflective region functions as a green fluorescent reflector. The specific configuration of the phosphor wheel 35 will be described later.

[0034] When the transmission region of phosphor wheel 35 is located at the position where the laser light is irradiated, the laser light is diffused in this transmission region while passing through phosphor wheel 35, and then is totally reflected by mirrors 38 and 39. Thereafter, this laser light passes through dichroic mirror 40, and is made into a light beam with a substantially uniform luminance distribution by integrator 41, and is then totally reflected by mirror 42 and emitted to mirror 20.

[0035] When the reflection area of ​​phosphor wheel 35 is located at the position irradiated with the laser light, the laser light (blue light) is converted into green light, and the converted green light is reflected by phosphor wheel 35 and then reflected by dichroic mirror 34. Thereafter, this green light is reflected by dichroic mirror 40, and is made into a light beam with a substantially uniform luminance distribution by integrator 41, and is then totally reflected by mirror 42 and emitted to mirror 20.

[0036] The red light emitted by the LED 32 passes through the dichroic mirror 34, is reflected by the dichroic mirror 40, is converted into a light beam with a substantially uniform brightness distribution by the integrator 41, is then totally reflected by the mirror 42, and is emitted to the mirror 20.

[0037] As described above, the dichroic mirror 34 has the spectral characteristics of transmitting blue light and red light while reflecting green light, while the dichroic mirror 40 has the spectral characteristics of transmitting blue light while reflecting red light and green light.

[0038] A rotation position detection mark is provided on the rotation shaft of the motor 37. An index sensor 36 is disposed at a position where the rotation position detection mark can be detected. The index sensor 36 is configured, for example, with a reflective photointerrupter (also called a reflective photosensor). The index sensor 36 generates an index signal that indicates the detection timing of the rotation position detection mark. The index sensor 36 then outputs the generated index signal to the light source driving unit 17.

[0039] Furthermore, an optical sensor (not shown) is disposed facing the light exit side of integrator 41. This optical sensor detects only the luminance regardless of the color of the light. Information on the luminance detected by the optical sensor is output to light source driving unit 17.

[0040] The light source driving unit 17 includes a counter 28. The counter 28 counts pulses of a lamp enable signal LAMP_ENBL generated by the projection processing unit 16. The light source driving unit 17 executes light emission processing based on the count value of the counter 28. The lamp enable signal LAMP_ENBL will be described in detail later.

[0041] [1-2] Phosphor wheel 35 configuration FIG. 3 is a plan view of the phosphor wheel 35 shown in FIG.

[0042] The phosphor wheel 35 is formed in an annular shape. A hole-shaped bearing 51 is provided at the center of the phosphor wheel 35. The bearing 51 is attached to the rotation shaft of the motor 37. The phosphor wheel 35 can be rotated by being driven by the motor 37.

[0043] The base material 50 of the phosphor wheel 35 is made of a metal such as copper or aluminum. The surface of the base material 50 facing the light source is mirror-finished by silver deposition or the like. The phosphor wheel 35 has a transmissive region 52 and a reflective region 53 arranged side by side in the circumferential direction.

[0044] Reflection region 53 of phosphor wheel 35 is provided on the mirror-finished surface of base material 50, and is configured by forming a green phosphor layer on base material 50. Reflection region 53 receives blue laser light (blue wavelength band light) emitted by semiconductor laser 31 as excitation light, and emits green light (green wavelength band light). This green light is reflected by phosphor wheel 35.

[0045] The transmissive region 52 of the phosphor wheel 35 is formed by fitting a translucent member into a cutout formed in the base material 50 of the phosphor wheel 35. The transparent member is made of a transparent material such as glass or resin. The transparent member may also be provided with a diffusion layer on the surface on the side irradiated with blue light or on the opposite side. The blue light incident on the transmissive region 52 is transmitted or diffused through the transmissive region 52.

[0046] One frame is the period during which phosphor wheel 35 makes one revolution. In one frame, the light of multiple colors that light source unit 18 can emit makes one revolution in a time-division manner. One revolution of phosphor wheel 35 is 360 degrees, and the timing of emitting light of each color can be expressed as an angle.

[0047] [1-3] Configuration of the projection processing unit 16 and the light source driving unit 17 FIG. 4 is a block diagram of the projection processing unit 16 and the light source driving unit 17 shown in FIG.

[0048] The projection processing unit 16 outputs a lamp enable signal LAMP_ENBL. The lamp enable signal LAMP_ENBL is set to be ON at the start timing of a spoke period and OFF at the end timing of the spoke period, and is output (also called a LAMP_ENBL pulse). In other words, the output state of the pulse signal (= lamp enable signal LAMP_ENBL) changes for each spoke period for switching the light color.

[0049] The projection processing unit 16 also outputs a red light emission signal RED_LED1, a green light emission signal GRN_LED1, and a blue light emission signal BLU_LED1. The red light emission signal RED_LED1 is a signal that instructs the projection unit 16 to emit red light. The green light emission signal GRN_LED1 is a signal that instructs the projection unit 16 to emit green light. The blue light emission signal BLU_LED1 is a signal that instructs the projection unit 16 to emit blue light. The lamp enable signal LAMP_ENBL, the red light emission signal RED_LED1, the green light emission signal GRN_LED1, and the blue light emission signal BLU_LED1 are sent to the light source driving unit 17.

[0050] The light source driving unit 17 includes a signal conversion circuit 60. The signal conversion circuit 60 includes three D flip-flops 61 to 63, an AND gate 64, and two inverters 65 and 66. The D flip-flops 61 to 63 transfer data at the rising edge of the clock and hold the data during other periods.

[0051] The input terminal D of this rising-edge type D flip-flop 61 receives the red light-emitting signal RED_LED1. The D flip-flop 61 outputs a green light-emitting signal GRN_LED2 of high level "1" from the output terminal Q in response to detecting the rising edge "↑" of the lamp enable signal LAMP_ENBL and the high level "1" of the red light-emitting signal RED_LED1. The D flip-flop 61 outputs a green light-emitting signal GRN_LED2 of low level "0" from the output terminal Q in response to detecting the rising edge "↑" of the lamp enable signal LAMP_ENBL and the low level "0" of the red light-emitting signal RED_LED1. As a result, the light source driver 17 controls the emission of green light using the red light-emitting signal output from the projection processor 16.

[0052] The input terminal of the inverter 65 receives the red light-emitting signal RED_LED1. The inverter 65 inverts the red light-emitting signal RED_LED1 and outputs an inverted signal INV1.

[0053] A first input terminal of the AND gate 64 receives the inverted signal INV1, and a second input terminal of the AND gate 64 receives the green light-emitting signal GRN_LED1. The AND gate 64 performs a logical AND operation and outputs a signal AND. The signal AND is also called a composite signal. An input terminal D of the D flip-flop 62 receives a signal AND from the AND gate 64. A clock terminal of the D flip-flop 62 receives a lamp enable signal LAMP_ENBL. The D flip-flop 62 outputs a blue light-emitting signal BLU_LED2 of high level "1" from an output terminal Q in response to detecting a rising edge "↑" of the lamp enable signal LAMP_ENBL and a high level "1" of the signal AND. The D flip-flop 62 also outputs a blue light-emitting signal BLU_LED2 of low level "0" from an output terminal Q in response to detecting a rising edge "↑" of the lamp enable signal LAMP_ENBL and a low level "0" of the signal AND. As a result, the light source driver 17 controls the emission of blue light (third color) using the red light-emitting (first color) signal and the green light-emitting (second color) signal output from the projection processor 16.

[0054] The input terminal of the inverter 66 receives the green light-emitting signal GRN_LED1. The inverter 66 inverts the green light-emitting signal GRN_LED1 and outputs an inverted signal INV2.

[0055] An input terminal D of the D flip-flop 63 receives the inverted signal INV2. A clock terminal of the D flip-flop 63 receives the lamp enable signal LAMP_ENBL. The D flip-flop 63 outputs a red light-emitting signal RED_LED2 of high level "1" from an output terminal Q in response to detecting a rising edge "↑" of the lamp enable signal LAMP_ENBL and a high level "1" of the inverted signal INV2. The D flip-flop 63 also outputs a red light-emitting signal RED_LED2 of low level "0" from an output terminal Q in response to detecting a rising edge "↑" of the lamp enable signal LAMP_ENBL and a low level "0" of the inverted signal INV2. As a result, the light source driver 17 controls the emission of red light using the green light-emitting signal output from the projection processor 16.

[0056] The light source driving unit 17 does not use the blue light emission signal BLU_LED1 transmitted from the projection processing unit 16.

[0057] The light source driving unit 17 operates to generate an emission signal for a second color different from the first color, using an emission signal for a first color generated by the projection processing unit 16. That is, the light source driving unit 17 generates a signal for green light, using a signal for red light generated by the projection processing unit 16. The light source driving unit 17 generates a signal for red light, using a signal for green light generated by the projection processing unit 16. The light source driving unit 17 generates a signal for blue light, using the signal for red light and the signal for green light generated by the projection processing unit 16. The light source driving unit 17 then controls the operation of the light source unit 14, using the green emission signal GRN_LED2, the blue emission signal BLU_LED2, and the red emission signal RED_LED2.

[0058] [2] Operation The operation of the projection device 10 configured as described above will be described. In this embodiment, the projection device 1 performs projection processing using four segments. A segment refers to the type of color of light that the light source unit 18 can emit. The four segments are, for example, red (R), green (G), blue (B), and yellow (Y). That is, the four segments are the three primary colors (the three primary colors of light) consisting of red light, green light, and blue light, plus a color other than the three primary colors, such as yellow light. In this specification, each of the four segments of light (for example, red light, green light, blue light, and yellow light) that the projection device 10 can emit is also referred to as monochromatic light.

[0059] (Operation of Comparative Example) First, a light source switching operation according to a comparative example will be described. Fig. 5 is a timing diagram illustrating the light source switching operation of a projection device according to a comparative example. The combined light in Fig. 5 is light emitted from the light source unit. In the comparative example, the projection processing unit generates a red light emission signal RED_LED1, a green light emission signal GRN_LED1, and a blue light emission signal BLU_LED1, and the projection processing unit operates to emit red light, yellow light, green light, and blue light.

[0060] As an example, the projection device emits light in the order of red (R), yellow (Y), green (G), and blue (B) in one frame.

[0061] The projection processing unit generates four LAMP_ENBL pulses per frame. The four LAMP_ENBL pulses specify the timing for switching on yellow light, green light, blue light, and red light. The number of LAMP_ENBL pulses is counted by a counter included in the light source driving unit. The light source driving unit determines the type of color to be emitted based on the count value of the counter. The width of the LAMP_ENBL pulse defines the spoke period SP. During the spoke period, the light source unit switches the color of light. In Figure 5, tx, which corresponds to the start timing of the spoke period, indicates the end timing of the spoke period.

[0062] At time t0, i.e., the beginning of one frame, the counter's count value is zero. The projection processing unit sets the red light-emitting signal RED_LED1 to high level "1." In this specification, a high level "1" of the signal means activation, and a low level "0" of the signal means deactivation. In response to the rising edge "↑" of the red light-emitting signal RED_LED1, the light source driving unit causes the light source unit to emit red light.

[0063] At time t1, the projection processor generates the first LAMP_ENBL pulse, causing the counter to count up to one.

[0064] At time t2, the projection processing unit sets the green light emitting signal GRN_LED1 to high level "1." The red light emitting signal RED_LED1 maintains high level "1." The rising edge "↑" of the green light emitting signal GRN_LED1 is set approximately in the center of the spoke period SP. In response to the rising edge "↑" of the green light emitting signal GRN_LED1, the light source driving unit controls the light source unit to turn on the red light source and the green light source. The light source unit emits yellow light by mixing the green light and the red light.

[0065] At time t3, the projection processor generates a second LAMP_ENBL pulse, and the counter value becomes 2.

[0066] At time t4, the projection processing unit sets the red light emitting signal RED_LED1 to low level "0." The green light emitting signal GRN_LED1 remains at high level "1." The falling edge of the red light emitting signal RED_LED1 is set to approximately the center of the spoke period SP. In response to the falling edge of the red light emitting signal RED_LED1, the light source driving unit causes the light source unit to emit green light.

[0067] At time t5, the projection processor generates a third LAMP_ENBL pulse, causing the counter to reach a count of three.

[0068] At time t6, the projection processing unit sets the green light-emitting signal GRN_LED1 to low level "0" and the blue light-emitting signal BLU_LED1 to high level "1." The rising edge "↑" of the blue light-emitting signal BLU_LED1 is set approximately in the center of the spoke period SP. In response to the rising edge of the blue light-emitting signal BLU_LED1, the light source driving unit causes the light source unit to emit blue light.

[0069] At time t7, the projection processor generates the fourth LAMP_ENBL pulse, causing the counter to count up to four.

[0070] At time t8, the projection processing unit sets the blue light-emitting signal BLU_LED1 to low level "0" and the red light-emitting signal RED_LED1 to high level "1." The rising edge "↑" of the red light-emitting signal RED_LED1 is set approximately in the center of the spoke period SP. The width of the fourth LAMP_ENBL pulse is set narrower than the width of the third LAMP_ENBL pulse, for example, but the spoke period SP corresponding to the fourth LAMP_ENBL pulse is set the same as the spoke period SP corresponding to the third LAMP_ENBL pulse. In response to the rising edge of the red light-emitting signal RED_LED1, the light source driving unit causes the light source unit to emit red light. Time t8 marks the end of one frame. Note that by setting the width of the fourth LAMP_ENBL pulse narrower than the widths of the first, second, and third LAMP_ENBL pulses, it becomes easier to check the cycle of one frame.

[0071] After four LAMP_ENBL pulses are generated, the index sensor activates the index signal. When the index signal is activated, the light source driver clears the counter to zero. Then, the light emission process of red, yellow, green, and blue light is repeated.

[0072] In the comparative example, the color switching timing is set to the center of the spoke period SP.

[0073] (Operation of the embodiment) Next, a light source switching operation according to the embodiment of the present invention will be described below. Fig. 6 is a timing chart illustrating the light source switching operation of the projection device 10 according to the embodiment.

[0074] As an example, the projection device 10 emits light in the order of red (R), yellow (Y), green (G), and blue (B) in one frame. The angles of R, Y, G, and B are just an example and can be set appropriately according to specifications.

[0075] 6, the waveforms of the LAMP_ENBL pulse, red light emission signal RED_LED1, green light emission signal GRN_LED1, and blue light emission signal BLU_LED1 are the same as those in the comparative example, and the projection processing unit 16 performs the same operation as in the comparative example. That is, the red light emission signal RED_LED1, green light emission signal GRN_LED1, and blue light emission signal BLU_LED1 are switched on / off in the center of the spoke period SP. Red light is also referred to as the first color light, green light as the second color light, and blue light as the third color light. The red light emission signal RED_LED1 is also referred to as the first signal, the green light emission signal GRN_LED1 as the second signal, and the blue light emission signal BLU_LED1 as the third signal.

[0076] At time t0, i.e., the beginning of one frame, the count value of the counter 28 is zero. The projection processing unit 16 sets the red light emission signal RED_LED1 to high level "1." The light source driving unit 17 causes the light source unit 18 to emit red light as a continuation of the operation of the immediately previous frame.

[0077] At time t1, the projection processing unit 16 generates the first LAMP_ENBL pulse. The count value of the counter 28 becomes 1. At time t1, because the rising edge of the LAMP_ENBL pulse (↑) and the inversion signal INV2 are at high level (1), the D flip-flop 63 maintains the red light-emitting signal RED_LED2 at high level (1). In addition, the D flip-flop 61 outputs the green light-emitting signal GRN_LED2, which becomes high level (1), from the output terminal Q in response to the rising edge of the LAMP_ENBL pulse (↑) and the red light-emitting signal RED_LED1 being at high level (1). The light source driving unit 17 controls the light source unit 18 to turn on the red and green light sources. The light source unit 18 emits yellow light by mixing green and red light. That is, the light source driving unit 17 issues an instruction to switch from red light to yellow light at the start timing of the spoke period SP.

[0078] At time t2, the projection processing unit 16 sets the green light emission signal GRN_LED1 to high level “1.” The light source driving unit 17 does not use this information.

[0079] At time t3, the projection processing unit 16 generates a second LAMP_ENBL pulse. The count value of the counter 28 becomes 2. At time t3, the signal conversion circuit 60 causes the D flip-flop 61 to output from the output terminal Q a green light-emitting signal GRN_LED2 that goes to high level "1" in response to the rising edge "↑" of the LAMP_ENBL pulse and the red light-emitting signal RED_LED1 going to high level "1." Furthermore, the D flip-flop 63 causes the output terminal Q to output a red light-emitting signal RED_LED2 that goes to low level "0" in response to the rising edge "↑" of the LAMP_ENBL pulse and the inversion signal INV2 going to low level "0." The light source driving unit 17 controls the light source unit 18 to keep the red light source off and the green light source on. The light source unit 18 emits green light.

[0080] At time t4, the projection processing unit 16 sets the red light emission signal RED_LED1 to low level “0.” The light source driving unit 17 does not use this information.

[0081] At time t5, the projection processing unit 16 generates a third LAMP_ENBL pulse. The count value of the counter 28 becomes 3. Based on the inversion signal INV1 and the green light-emitting signal GRN_LED1, the signal AND of the AND gate 64 becomes high level "1." In response to the input of the rising edge "↑" of the LAMP_ENBL pulse and the high level "1" of the signal AND, the D flip-flop 62 outputs the blue light-emitting signal BLU_LED2 from the output terminal Q, which becomes high level "1." At time t5, the red light-emitting signal RED_LED1 maintains low level "0." In response to the input of the rising edge "↑" of the LAMP_ENBL pulse and the red light-emitting signal RED_LED1 "0," the D flip-flop 61 outputs the green light-emitting signal GRN_LED2 from the output terminal Q, which becomes low level "0." The light source driving unit 17 controls the light source unit 18 to turn off the green light source and turn on the blue light source. The light source unit 18 emits blue light.

[0082] At time t6, the projection processing unit 16 sets the green light emitting signal GRN_LED1 to low level "0" and the blue light emitting signal BLU_LED1 to high level "0." The light source driving unit 17 does not use this information.

[0083] At time t7, the projection processing unit 16 generates a fourth LAMP_ENBL pulse. The count value of the counter 28 becomes 4. At time t7, the D flip-flop 63 outputs a red light-emitting signal RED_LED2 from the output terminal Q, which becomes high level "1," in response to the rising edge "↑" of the LAMP_ENBL pulse and the high level "1" of the inversion signal INV2. Also at time t7, the D flip-flop 62 outputs a blue light-emitting signal BLU_LED2 from the output terminal Q, which becomes low level "0," in response to the rising edge "↑" of the LAMP_ENBL pulse and the low level "0" of AND. The light source driving unit 17 controls the light source unit 18 to turn off the blue light source and turn on the red light source. The light source unit 18 emits red light.

[0084] At time t8, the projection processing unit 16 sets the blue light emitting signal BLU_LED1 to low level "0" and the red light emitting signal RED_LED1 to high level "1." This information is not used by the light source driving unit 17. Time t8 is the end of one frame.

[0085] After four LAMP_ENBL pulses are generated, the index signal is activated by the index sensor 36. When the index signal is activated, the light source driver 17 clears the count value of the counter 28 to zero. After that, the light emission process of red light, yellow light, green light, and blue light is repeated.

[0086] [3] Effects of the embodiment According to the embodiment, the projection device 10 can start the process of switching from a first color light to a second color light different from the first color at the beginning of the spoke period SP (i.e., at the timing when the LAMP_ENBL pulse rises). By starting the switching process earlier than in the comparative example, it becomes possible to use a light source with a slow startup response (taking time to reach maximum brightness). Furthermore, by using this patent, the spoke period can theoretically be halved.

[0087] Furthermore, the brightness of the monochromatic light in one frame can be improved, thereby improving the display characteristics of the projection device 10.

[0088] Furthermore, it is possible to increase the light emission period of any one of the RGB colors in the spoke period SP, thereby improving the display characteristics of the RGB single colors.

[0089] [4] Other Examples In this embodiment, one functional block may be configured as a single piece of hardware, a single piece of software, or a combination thereof.

[0090] The functional configuration in this embodiment is realized by a processor that executes arithmetic processing, and processors that can be used in this embodiment include those that are composed of various processing devices alone, such as single processors, multiprocessors, and multicore processors, as well as those that combine these various processing devices with processing circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays).

[0091] When a series of processes is executed by software, the programs that make up the software are installed into a computer or the like from a network or a recording medium.

[0092] The computer may be a computer built into dedicated hardware, or may be a computer capable of executing various functions by installing various programs, such as a general-purpose personal computer.

[0093] The recording medium containing such a program may be a removable medium distributed separately from the device main body to provide the program to the user, or may be a recording medium provided to the user in a state where it is pre-installed in the device main body. Removable media may be, for example, a magnetic disk, an optical disk, or a magneto-optical disk. Optical disks may be, for example, CD-ROMs (Compact Disk-Read Only Memory), DVDs (Digital Versatile Disks), Blu-ray (registered trademark) Discs, etc. Magneto-optical disks may be, for example, MDs (Mini-Disks). Furthermore, recording media provided to the user in a state where it is pre-installed in the device main body may be, for example, a semiconductor memory included in a storage unit in which the program is recorded.

[0094] The steps of writing a program to be recorded on a recording medium include not only processes that are performed in chronological order, but also processes that are not necessarily performed in chronological order but are performed in parallel or individually.

[0095] Although the embodiment of the present invention has been described using a rising edge type D flip-flop as an example, a falling edge type D flip-flop may be used if the output signal of the LAMP_ENBL pulse is inverted.

[0096] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0097] The inventions described in the original claims of this application are set forth below.

[0098] [Claim 1] A projection device comprising a light source driving unit that controls a light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color.

[0099] [Claim 2] the light source driving unit outputs a light emission signal for causing the light source unit to emit the third color light, based on a pulse signal whose output state changes for each spoke period for switching the color of light, the first signal, and the second signal. 2. The projection device of claim 1.

[0100] [Claim 3] the light source driving unit outputs the light emission signal that rises at the rising edge of the pulse signal when a composite signal generated based on the first signal and the second signal is at a high level, and controls the light source unit to emit the third color light based on the output light emission signal. 3. The projection device according to claim 2.

[0101] [Claim 4] the light source driver includes a rising edge type D flip-flop; an input terminal of the D flip-flop receives a composite signal generated based on the first signal and the second signal; The clock terminal of the D flip-flop receives the pulse signal, The D flip-flop outputs the light emission signal from an output terminal. 4. The projection device according to claim 2 or 3.

[0102] [Claim 5] the light source driving unit outputs the light emission signal that rises not at the center timing of the spoke period but at the start timing of the spoke period. 5. The projection device according to claim 3 or 4.

[0103] [Claim 6] The light emitted by the light source unit is four segments of blue light, red light, green light, and yellow light. 6. A projection device according to claim 1.

[0104] [Claim 7] The computer controlling the light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color; Projection method.

[0105] [Claim 8] On the computer, controlling the light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color; A program that executes a process. [Explanation of symbols]

[0106] 10…Projection device 11...Input / output connector 12...Input / output interface 13...Bus 14...Image conversion unit 14...Light source section 15...VRAM 16...Projection processing unit 17...Light source drive unit 18...Light source section 19...Micromirror element 20...Mirror 21...Projection lens section 22...Audio processing unit 23...Speaker 24...CPU 25...Storage section 26...Operation unit 27…Power circuit 28...Counter 31...Semiconductor laser 32...LED 33, 38, 39, 42...Mirror 34...Dichroic mirror 35...Phosphor wheel 36...Index sensor 37...Motor 40...Dichroic mirror 41...Integrator 50...Base material 51...Bearing 52…Transmission area 53…Reflection area 60...Signal conversion circuit 61~63...D flip-flop 64...AND gate 65,66...Inverter

Claims

1. a light source driver that controls the light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color, the light source driving unit outputs a light emission signal that rises at the start timing of a spoke period, which is a period during which a composite signal generated based on the first signal and the second signal is at a high level and for switching the color of light, and goes to a high level at the start timing of the spoke period and goes to a low level at the end timing, and controls the light source unit to emit light of the third color based on the output light emission signal. Projection device.

2. the light source driver includes a rising edge type D flip-flop; an input terminal of the D flip-flop receives a composite signal generated based on the first signal and the second signal; The clock terminal of the D flip-flop receives the pulse signal, The D flip-flop outputs the light emission signal from an output terminal. The projection device according to claim 1 .

3. The composite signal is generated by a logical AND of an inverted signal obtained by inverting the polarity of the first signal and the second signal.

3. The projection device according to claim 1 or 2.

4. The light emitted by the light source unit is four segments of blue light, red light, green light, and yellow light.

4. A projection device according to claim 1.

5. The computer controlling the light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color; a light emitting signal that rises at the start timing of a spoke period, which is a period during which a composite signal generated based on the first signal and the second signal is in a high level state and for switching the color of light, and goes to a high level at the start timing of the spoke period and goes to a low level at the end timing of the spoke period, and controls the light source unit to emit light of the third color based on the output light emitting signal. Projection method.

6. On the computer, controlling the light source unit to emit light of a third color different from the first color and the second color based on a first signal for a first color and a second signal for a second color different from the first color; a light emitting signal that rises at the start timing of a spoke period, which is a period during which a composite signal generated based on the first signal and the second signal is in a high level state and for switching the color of light, and goes to a high level at the start timing of the spoke period and goes to a low level at the end timing of the spoke period, and controls the light source unit to emit light of the third color based on the output light emitting signal. A program that executes a process.

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