Projection device, projection method, and program

Abstract

To provide a projection device capable of improving the luminance of emitted light.SOLUTION: A projection device 10 includes a light source unit 18 that cyclically emits light of multiple colors in time division, and a control unit 24. The light source unit 18 can emit light of a first color and light of a second color that is higher in luminance than the first color. The control unit 24 generates a plurality of pulses for switching the color of light emitted from the light source unit 18, and makes a period during which the light of the second color is emitted longer than a period during which the light of the first color is emitted, based on a first pulse for emitting the light of the first color, a second pulse for switching the emitted light from the light of the first color to the light of the second color, and a third pulse for switching the emitted light from the light of the second color to light of a third color, among the plurality of pulses.SELECTED DRAWING: Figure 8

Description

Technical Field

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

Background Art

[0002] A projector as a projection device that projects an image such as an image based on image data stored in a screen of a personal computer, a video image, a memory card, etc. onto a screen is widely used. This projector condenses the light emitted from a light source onto a micromirror element called a DMD (Digital Micromirror Device) or a liquid crystal panel, and displays a color image on the screen.

[0003] There are projectors on the market that use a combination of semiconductor light-emitting elements that emit monochromatic light, such as LD (semiconductor laser) and LED (light-emitting diode), instead of a discharge lamp that emits white light, in the light source unit of the projector.

[0004] The light source unit of the projector emits, for example, red light, green light, and blue light cyclically in a time-sharing manner. Generally, in the light source unit of the projector, red light, green light, and blue light are set in good balance. In this case, the brightness is set to be considerably suppressed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention provides a projection device, a projection method, and a program capable of improving the brightness of emitted light.

Means for Solving the Problems

[0007] A projection device according to one aspect of the present invention comprises a light source unit that cyclically emits multiple colors of light in a time-division manner, and a control unit, wherein the light source unit is capable of emitting a first color of light and a second color of light having a higher brightness than the first color, and the control unit generates a plurality of pulses for switching the color of the light emitted from the light source unit, and based on the plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the control unit sets the period for emitting the second color of light to be longer than the period for emitting the first color of light. The light source unit mixes the first color of light with the third color of light to emit the second color of light. do. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a projection device, projection method, and program that can improve the brightness of emitted light. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram of a projection device according to the first embodiment. [Figure 2] Figure 2 is a block diagram of the light source unit shown in Figure 1. [Figure 3] Figure 3 is a plan view of the phosphor wheel shown in Figure 2. [Figure 4] Figure 4 is a flowchart illustrating the overall operation of the projection device. [Figure 5] Figure 5 illustrates an example of the modes available to a projection device. [Figure 6] Figure 6 is a flowchart illustrating the light source switching operation of the projection device. [Figure 7] Figure 7 is a timing diagram illustrating the light emission process of the projection device in the normal mode according to the first embodiment. [Figure 8] Figure 8 is a timing diagram illustrating the light emission process of the projection device in the brightness-up mode according to the first embodiment. [Figure 9] Figure 9 is a timing diagram illustrating the light emission process of the projection device in the normal mode according to the second embodiment. [Figure 10] Figure 10 is a timing diagram illustrating the light emission process of the projection device in the brightness-up mode according to the second embodiment. [Modes for carrying out the invention]

[0010] Embodiments will be described below with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and proportions in each drawing are not necessarily the same as those in reality. The following embodiments are illustrative examples of devices and methods for realizing the technical concept of the present invention, and the technical concept of the present invention is not defined by the shape, structure, arrangement, etc. of the components. In the following description, elements having the same function and configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] [1] First Embodiment [1-1] Configuration of the projection device 10 Figure 1 is a block diagram of a projection device 10 according to a first embodiment of the present invention. The projection device 10 is configured, for example, as a projector compliant with the DLP (Digital Light Processing) method.

[0012] 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 drive unit 17, a light source unit (light source device) 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 which is a processor, a memory unit 25, an operation unit 26, and a power supply circuit 27.

[0013] 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 the bus 13 so that they can transmit and receive data to and from each other.

[0014] The input / output connector 11 is a terminal for inputting image data on which the projection device 10 projects 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-sub15 type RGB input terminal, a USB (Universal Serial Bus) connector, and the like. Further, a removable medium composed of a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like storing a program, image data, and the like is appropriately attached to the input / output connector 11.

[0015] The program read from the removable medium by the input / output connector 11 is stored in the storage unit 25 as necessary. Further, the removable medium can also store various data stored in the storage unit 25 in the same manner as the storage unit 25.

[0016] The image data conforming to various standards input to the input / output connector 11 is transmitted to the image conversion unit 14 via the input / output interface 12 and the bus 13.

[0017] The image conversion unit 14 converts the image data transmitted from the input / output connector 11 into an image signal in a predetermined format suitable for projection. Further, the image conversion unit 14 transmits the converted image signal to the projection processing unit 16.

[0018] The VRAM 15 is a buffer memory for image processing. The VRAM 15 is appropriately used as a buffer when transmitting an image signal from the image conversion unit 14 to the projection processing unit 16.

[0019] The projection processing unit 16 drives the micromirror elements 19 by time-division drive, which is calculated by multiplying the frame rate, the number of color component divisions, and the number of display gradations in accordance with a predetermined format, according to the image signal transmitted from the image conversion unit 14.

[0020] The micromirror element 19 is a spatial light modulation element driven based on the control of the projection processing unit 16. The micromirror element 19 comprises multiple micromirrors, each corresponding to multiple pixels arranged in an array (for example, 1024 horizontal pixels × 768 vertical pixels corresponding to XGA), similar to a DMD (Digital Micromirror Device). The micromirror element 19 rapidly switches the tilt angle of each of the multiple micromirrors on and off. When the micromirrors are on, the micromirror element 19 forms an optical image corresponding to the image signal by reflected light emitted from the projection lens unit 21.

[0021] The light source unit 18 cyclically emits multiple colors of light (including primary color light of R (red), G (green), and B (blue)) in a time-division manner. This multiple-color light from the light source unit 18 undergoes total internal reflection by the mirror 20 and irradiates the micromirror element 19.

[0022] The projection processing unit 16 adjusts the color so that it corresponds to the color components of the input image signal by adjusting the time that the micromirror element 19 is turned on for a predetermined period of time for each of the multiple colors of light incident on the micromirror element 19. Then, a light image is formed by the light reflected from the micromirror element 19, and the formed light image is projected and displayed on a projection surface such as a screen (not shown) via the projection lens unit 21.

[0023] The projection device 10 may be equipped with a CPU (hereinafter referred to as the projection processing CPU) for performing projection processing using the DLP method. In this case, the projection processing CPU, which is a processor, may control the projection processing unit 16.

[0024] The light source drive unit 17 controls the emission timing and emission intensity of the semiconductor laser and LEDs included in the light source unit 18, as well as the rotation of the phosphor wheel 35 (see Figure 2) by the motor, based on timing signals in the image signal transmitted from the projection processing unit 16, index signals input from the index sensor 36 (described later), brightness information input from the light sensor (not shown), etc. The control by the light source drive unit 17 is performed based on overall control by the CPU 24.

[0025] The audio processing unit 22 is equipped with a sound source circuit such as a PCM (Pulse Code Modulation) sound source. The audio processing unit 22 converts the audio data transmitted from the CPU 24 during projection operation into analog and drives the speaker 23 to amplify and emit sound.

[0026] The memory unit 25 includes ROM (Read Only Memory) as non-volatile memory and RAM (Random Access Memory) as volatile memory. The ROM stores various programs and various data. The ROM also stores the rated current values ​​for the LEDs and semiconductor lasers when R, G, and B light is emitted, in the factory-set white-balance state. The RAM is used as the work memory for the CPU 24.

[0027] The CPU 24 comprehensively controls the operation of each of the above circuits. The CPU 24 is also called the control unit. If the projection device 10 is equipped with the projection processing CPU, the control unit includes the CPU 24 and the projection processing CPU. The CPU 24 executes various processes based on programs stored in ROM or programs loaded into RAM from removable media. The RAM appropriately stores data necessary for the CPU 24 to execute various processes.

[0028] The projection device 10 may further include a ROM in which a program for the projection processing CPU to perform projection processing is stored, and a RAM in which data necessary for the projection processing CPU to perform various processes is appropriately stored.

[0029] The CPU 24 performs adjustment operations for various projection operations in response to operation signals, which are signals based on key operations received by the user from the operation unit 26.

[0030] 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 projection device 10 and a remote controller (not shown) dedicated to the projection device 10. The operation unit 26 is equipped with, 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 on both the key operation unit and the remote controller. The operation unit 26 transmits operation signals based on key operations entered by the user to the CPU 24.

[0031] The power supply circuit 27 uses an externally supplied power source to generate various voltages necessary 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 may also include a battery. If the supply of external power is interrupted, the power supply circuit 27 may use the battery to generate various voltages and supply them to the corresponding circuits.

[0032] [1-1-1] Configuration of the light source unit 18 Figure 2 is a block diagram of the light source unit 18 shown in Figure 1. The light source unit 18 includes a semiconductor laser 31 for B emission, an LED 32 for R emission, 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).

[0033] The light source unit 18 is equipped with two types of light-emitting elements (light sources). Specifically, the light source unit 18 is equipped with a semiconductor laser 31 as a first light source that emits blue laser light (also called blue light) and an LED 32 as a second light source that emits red light. In Figure 2, the letters R, G, and B, and the arrows represent the color of the light (one of R, G, and B) and the direction of light propagation.

[0034] The blue laser light emitted by the semiconductor laser 31 is totally reflected by the mirror 33, then passes through the dichroic mirror 34, and irradiates a portion of the circumference of the phosphor wheel 35.

[0035] The phosphor wheel 35 is composed of an annular member and is connected to the rotation axis of the motor 37. The phosphor wheel 35 is rotated at a constant speed by the motor 37. The circumference of the phosphor wheel 35, which is irradiated with laser light, is provided with a light-transmitting region and a light-reflecting region. The light-transmitting region of the phosphor wheel 35 functions as a diffuser plate that diffuses light. The light-reflecting region of the phosphor wheel 35 is coated with fluorescent paint, and this light-reflecting region functions as a green fluorescent reflector. The specific configuration of the phosphor wheel 35 will be described later.

[0036] When the transparent region of the phosphor wheel 35 is at the irradiation position of the laser beam, the laser beam is diffused in this transparent region, passes through the phosphor wheel 35, and is then totally reflected by mirrors 38 and 39, respectively. Subsequently, this laser beam passes through the dichroic mirror 40, is made into a light beam with a nearly uniform brightness distribution by the integrator 41, is totally reflected by mirror 42, and is emitted to mirror 20.

[0037] When the reflective area of ​​the phosphor wheel 35 is at the laser beam irradiation position, the laser beam (blue light) is converted to green light. After the converted green light is emitted from the phosphor wheel 35, it is reflected by the dichroic mirror 34. Subsequently, this green light is reflected by the dichroic mirror 40, and after being made into a light beam with a nearly uniform brightness distribution by the integrator 41, it is totally reflected by the mirror 42 and emitted to the mirror 20.

[0038] The red light emitted by LED32 passes through the dichroic mirror 34, is reflected by the dichroic mirror 40, and after being converted into a light beam with a nearly uniform brightness distribution by the integrator 41, it is totally reflected by mirror 42 and emitted to the mirror 20.

[0039] As described above, the dichroic mirror 34 has spectral properties that transmit blue and red light while reflecting green light. Similarly, the dichroic mirror 40 has spectral properties that transmit blue light while reflecting red and green light.

[0040] A rotation position detection mark is provided on the rotation axis of the motor 37. An index sensor 36 is positioned at a location where the rotation position detection mark can be detected. The index sensor 36 is composed of, for example, a reflective photointerrupter (also called a reflective photosensor). The index sensor 36 generates an index signal indicating the detection timing of the rotation position detection mark. The index sensor 36 then outputs the generated index signal to the light source drive unit 17.

[0041] Furthermore, a light sensor (not shown) is positioned facing the light-emitting side of the integrator 41. This light sensor detects only the brightness, regardless of the color of the light. The brightness information detected by the light sensor is output to the light source drive unit 17.

[0042] The light source drive unit 17 includes a counter 28. The counter 28 counts the pulses of the lamp enable signal LAMP_ENBL generated by the projection processing unit 16. The light source drive unit 17 performs the light emission process based on the count value of the counter 28. Details of the lamp enable signal LAMP_ENBL will be described later.

[0043] [1-1-2] Configuration of the phosphor wheel 35 Figure 3 is a plan view of the phosphor wheel 35 shown in Figure 2.

[0044] The phosphor wheel 35 is configured 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 rotating shaft of the motor 37. The phosphor wheel 35 can be rotated by the drive of the motor 37.

[0045] The substrate 50 of the phosphor wheel 35 is made of a metal such as copper or aluminum. The surface of the substrate 50 on the light source side is mirror-finished by silver deposition or the like. The phosphor wheel 35 has a transmissive region 52 and a reflective region 53 arranged in the circumferential direction.

[0046] The reflective region 53 of the phosphor wheel 35 is provided on the mirrored surface of the substrate 50 and is formed by creating a green phosphor layer on the substrate 50. The reflective region 53 receives blue laser light (blue wavelength band light) emitted by the semiconductor laser 31 as excitation light and emits green light (green wavelength band light).

[0047] The transparent region 52 of the phosphor wheel 35 is formed by inserting a light-transmitting transparent 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. A diffusion layer may also be provided on the surface of the transparent member on the side irradiated with blue light or the opposite side. Blue light incident on the transparent region 52 is transmitted or diffusely transmitted through the transparent region 52.

[0048] One frame is the time it takes for the phosphor wheel 35 to complete one rotation. In one frame, the light source unit 18 emits multiple colors of light in a time-division manner. The rotation of the phosphor wheel 35 is considered to be 360 ​​degrees, and the timing of the emission of each color of light can be expressed as an angle.

[0049] [1-2] Operation The operation of the projection device 10 configured as described above will now be explained.

[0050] [1-2-1] Overall Operation First, let's explain the overall operation of the projection device 10. Figure 4 is a flowchart illustrating the overall operation of the projection device 10.

[0051] The user turns on the power to the projection device 10. The control unit 24 selects the mode that was in when the power was last turned off (step S100). Note that when the projection device 10 is first started up, the initially set mode is selected.

[0052] Figure 5 illustrates an example of the modes available to the projection device 10. The projection device 10 has four modes, M0 to M3. The names of modes M0 to M3 are, for example, “Bright”, “Light Control 7”, “Light Control 7 (3Seg)”, and Brightness Up Mode. Brightness Up Mode is a mode newly introduced in this embodiment and is capable of increasing brightness. “Bright”, “Light Control 7”, and “Light Control 7 (3Seg)” are examples of conventional normal modes. In “Bright”, “Light Control 7”, and Brightness Up Mode, projection processing is performed using 4 segments (4Seg). In “Light Control 7 (3Seg)”, projection processing is performed using 3 segments (3Seg). A segment is a type of light color that the light source unit 18 can emit. The 3 segments are, for example, red (R), green (G), and blue (B). The four segments are, for example, red (R), green (G), blue (B), and yellow (Y).

[0053] "Bright" and "Light Control 7" have different settings for the angles of each segment. In "Bright," the angles of green and yellow are set to be larger. In "Light Control 7," the angle of red is set to be larger. For example, the angles of "Bright" are set to R=90, Y=90, G=120, B=60. For example, the angles of "Light Control 7" are set to R=150, Y=50, G=100, B=60.

[0054] Next, the control unit 24 activates the selected mode (step S101).

[0055] Next, the control unit 24 selects the light emission process according to the selected mode (step S102). In modes M0, M1, and M3, the control unit 24 performs a 4-segment GBRY light source switching operation. In mode M2, the control unit 24 performs a 3-segment GBR light source switching operation. Details of the light source switching operation will be described later.

[0056] Next, the control unit 24 performs projection processing (step S103). In projection processing, the light source drive unit 17 controls the light source unit 18 to emit the desired light. The projection processing unit 16 also controls the operation of the micromirror element 19 to form a light image.

[0057] Next, the control unit 24 determines whether or not a key included in the operation unit 26 has been operated (step S104). The keys determined in step S104 are the mode key for switching modes and the OFF key for turning off the light source unit 18.

[0058] If no key is pressed (step S104=No), the control unit 24 continues the projection process.

[0059] If a mode switch is instructed by the mode key included in the operation unit 26 (step S104 = mode switch), the control unit 24 selects the mode instructed by the user (step S105). Subsequently, the control unit 24 repeats the process from step S101.

[0060] If the OFF key included in the operation unit 26 is pressed (step S104 = OFF key), the control unit 24 turns off the light from the light source unit 18 and terminates the projection process (step S106).

[0061] [1-2-2] Light source switching operation Next, we will explain the light source switching operation. Figure 6 is a flowchart illustrating the light source switching operation of the projection device 10.

[0062] In this embodiment, the projection device 10 emits light in the order of green (G), blue (B), red (R), and yellow (Y) within one frame.

[0063] The projection processing unit 16 generates a lamp enable signal LAMP_ENBL. The lamp enable signal LAMP_ENBL is a signal that specifies the timing for switching the color of light, and a pulse (called a LAMP_ENBL pulse) is generated at the timing for switching the color of light. In other words, the projection processing unit 16 generates multiple LAMP_ENBL pulses while the phosphor wheel 35 completes one rotation. The projection device 10 switches the color of the light emitted from the light source unit 18 at the rising edge of the LAMP_ENBL pulse.

[0064] The light source drive unit 17 performs a light emission process that emits light of the corresponding color according to the count value of the LAMP_ENBL pulse (step S200). At the beginning of one frame, the count value of the LAMP_ENBL pulse is zero. At the beginning of one frame, the light source drive unit 17 performs a light emission process that emits green light. Details of the light emission process will be described later.

[0065] Next, the projection processing unit 16 generates a LAMP_ENBL pulse (step S201).

[0066] Next, the light source drive unit 17 counts the LAMP_ENBL pulses using the counter 28 (step S202).

[0067] Next, the light source drive unit 17 determines whether or not the index signal has been activated (whether or not the signal state has changed) using the index sensor 36 (step S203). The index signal is activated each time the phosphor wheel 35 completes one rotation. In this embodiment, the index signal is activated each time the four segments (for example, G, B, R, and Y) cycle and emit light.

[0068] The light source drive unit 17 performs light emission processing according to the count value in step S200 until the index signal is activated. That is, if the count value of the counter 28 is 1, the light source drive unit 17 performs light emission processing to emit blue light. If the count value of the counter 28 is 2, the light source drive unit 17 performs light emission processing to emit red light. If the count value of the counter 28 is 3, the light source drive unit 17 performs light emission processing to emit, for example, yellow light. If the count value of the counter 28 is 4, the light source drive unit 17 performs light emission processing to emit the first color of the frame, i.e., green light.

[0069] After four LAMP_ENBL pulses are generated, the index signal is activated. When the index signal is activated, the light source drive unit 17 clears the count value of the counter 28 to zero (step S204). Subsequently, the light emission process for G, B, R, and Y is repeated.

[0070] [1-2-3] Normal Mode Next, we will explain the operation of the normal mode. The normal mode is a mode other than the brightness-up mode, and is one of the modes M0 to M2 mentioned above. The normal mode is also called the first mode. As an example of the normal mode, we will explain using mode M1. Mode M1 performs projection processing using four segments: G, B, R, and Y.

[0071] Figure 7 is a timing diagram illustrating the light emission process of the projection device 10 in normal mode. The angles G, B, R, and Y are examples and can be set as appropriate according to the specifications. In Figure 7, the semiconductor laser 31 for B emission is represented as a blue LD, the phosphor wheel 35 as a FW, and the LED 32 for R emission as a red LED. The combined light is the light emitted from the light source unit 18.

[0072] Time t0 is the start timing of the frame (frame switching timing). At time t0, the light source drive unit 17 turns on the semiconductor laser 31 and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits green light toward the mirror 20.

[0073] At time t1, the projection processing unit 16 generates the first LAMP_ENBL pulse. In response to the rising edge of the first LAMP_ENBL pulse, the light source drive unit 17 maintains the semiconductor laser 31 on and the LED 32 off. The phosphor wheel 35 transmits the blue light from the semiconductor laser 31. The light source unit 18 emits blue light toward the mirror 20.

[0074] The spoke period SP is preset based on the spot diameter of the light source (semiconductor laser 31) irradiated onto the phosphor wheel 35. The spoke period is a set period for switching colors, during which multiple colors of light are temporarily mixed when switching colors. During the spoke period, the light source unit 18 switches the color of the light. In one embodiment, by controlling the operation of the micromirror element 19, the light during the spoke period may not be used at all, and black may be projected during the spoke period. The projection of black is achieved by turning off the mirror of the corresponding pixel in the micromirror element 19. The LAMP_ENBL pulse is generated for each spoke period and is generated in accordance with the start timing of the spoke period. In other words, the timing of the rising edge of the LAMP_ENBL pulse and the start timing of the spoke period are the same. The width of the LAMP_ENBL pulse can be set arbitrarily. In this embodiment, the width of the LAMP_ENBL pulse is the same as the spoke period SP. In this embodiment, the time tx corresponding to the falling edge of the LAMP_ENBL pulse indicates the end timing of the spoke period.

[0075] At time t2, the projection processing unit 16 generates the second LAMP_ENBL pulse. In response to the rising edge of the second LAMP_ENBL pulse, the light source drive unit 17 turns off the semiconductor laser 31 and turns on the LED 32. The light source unit 18 emits red light toward the mirror 20.

[0076] At time t3, the projection processing unit 16 generates the third LAMP_ENBL pulse. In response to the rising edge of the third LAMP_ENBL pulse, the light source drive unit 17 turns on the semiconductor laser 31 and keeps the LED 32 on. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The LED 32 emits red light. The light source unit 18 mixes the green and red light and emits yellow light toward the mirror 20.

[0077] At time t4, the projection processing unit 16 generates the fourth LAMP_ENBL pulse. In response to the rising edge of the fourth LAMP_ENBL pulse, the light source drive unit 17 keeps the semiconductor laser 31 on and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits the green light toward the mirror 20.

[0078] In this way, the projection device 10 emits green light, blue light, red light, and yellow light in that order within one frame. Subsequently, the operation for one frame shown in Figure 7 is repeated.

[0079] Furthermore, the current values ​​of the semiconductor laser 31 and LED 32 may be changed at the timing of switching the color of light during the light emission process.

[0080] In normal mode, the brightness levels of green, blue, red, and yellow light are, for example, as follows, in descending order of brightness: 1. Blue light (B): 20[lm] 2.Red light (R): 100[lm] 3. Green light (G): 1500[lm] 4.Yellow light (Y):2000[lm] In terms of brightness, blue light has the lowest brightness, followed by red light (also called primary light), and then yellow light (also called secondary light).

[0081] [1-2-4] Brightness Boost Mode Next, the operation of the brightness-up mode will be explained. The brightness-up mode is the same as the previously mentioned mode M3. The brightness-up mode is also called the second mode. In brightness-up mode, the brightness of the projection device 10 is increased by keeping the yellow light, which has the highest brightness, lit for a longer period than in normal mode.

[0082] Figure 8 is a timing diagram illustrating the light emission process of the projection device 10 in the brightness-up mode. The angles G, B, R, and Y are examples and are based on, for example, the angles of the normal mode described above.

[0083] The emission processing of green and blue light is the same as in the normal mode described in Figure 7.

[0084] At times t2 and t3, the projection processing unit 16 generates a second LAMP_ENBL pulse (a pulse for performing a light emission process that emits the first color of light; also called the first pulse) and a third LAMP_ENBL pulse (a pulse for performing a light emission process that emits the second color of light; also called the second pulse) at predetermined intervals. Based on the first pulse, the second pulse, and the third pulse (the fourth LAMP_ENBL pulse described later, which is a pulse for performing a light emission process that emits the third color of light (green in this embodiment)), the projection processing unit 16 makes the period for emitting the second color of light (the period from the second pulse to the third pulse described later, i.e., period t3-t4; also called the first period) longer than the period for emitting the first color of light (the period from the first pulse to the second pulse, i.e., period t2-t3; also called the second period).

[0085] In this embodiment, the interval between the first pulse and the second pulse in the second mode (second period) is controlled to be shorter than the interval between the first pulse and the second pulse in the first mode. In this embodiment, the first period is lengthened by the amount that the second period is shortened.

[0086] Specifically, at times t2 and t3, the projection processing unit 16 generates the second and third LAMP_ENBL pulses consecutively. That is, the third LAMP_ENBL pulse (second pulse) is generated immediately after the second LAMP_ENBL pulse (first pulse). The width of the second LAMP_ENBL pulse, the width of the third LAMP_ENBL pulse, and the interval between the second and third LAMP_ENBL pulses are set to be as short as possible within the configurable range. In other words, the interval between the second and third LAMP_ENBL pulses is the shortest possible interval within the configurable range. In one embodiment, the projection processing unit 16 may control the interval between the second and third LAMP_ENBL pulses in the second mode to be shorter than a predetermined reference interval. The above reference interval can be arbitrarily set by the user.

[0087] In response to the rising edge of the second LAMP_ENBL pulse, the light source drive unit 17 turns off the semiconductor laser 31 and turns on the LED 32. In this state, red light is emitted from the light source unit 18 for a period of t2-t3.

[0088] In response to the rising edge of the third LAMP_ENBL pulse, the light source drive unit 17 turns on the semiconductor laser 31 and keeps the LED 32 on. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The LED 32 emits red light. The light source unit 18 emits yellow light by mixing the green and red light toward the mirror 20. In brightness-up mode, the light color is not switched during the spoke period (spoke period SP shown by a dashed line in Figure 8) for switching the light color from red to yellow in the normal mode in which projection processing is performed using 4 segments. Instead, the light color is switched from red to yellow at a time before the spoke period for switching the light color from red to yellow. That is, in brightness-up mode, the light source drive unit 17 controls the light source unit 18 to emit yellow light during the period in the normal mode in which red light is emitted for projection processing using 4 segments. During the period t3-t4, the light source unit 18 emits yellow light. In this embodiment, the second pulse is located within the spoke period SP (specifically, the spoke period for switching the color of the emitted light from blue to red). In this case, the second period is also located within the spoke period. In this embodiment, the first and second pulses are located within the same spoke period SP. By placing the second period within the spoke period, the projection device 10 can emit yellow light instead of red light after blue light. In one embodiment, the second pulse may be located outside the spoke period.

[0089] At time t4, the projection processing unit 16 generates the fourth LAMP_ENBL pulse (third pulse). In response to the rising edge of the fourth LAMP_ENBL pulse, the light source drive unit 17 keeps the semiconductor laser 31 on and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits the green light toward the mirror 20.

[0090] In this way, the projection device 10 emits green light, blue light, and yellow light in that order within one frame. Subsequently, the operation for one frame shown in Figure 8 is repeated. Note that the brightness-up mode is defined as a 4-segment light emission process because it is controlled to emit red light only for a short period (period t2-t3).

[0091] [1-3] Effects of the first embodiment As detailed above, in the first embodiment, the projection device 10 is newly equipped with a brightness-up mode for improving brightness. In the brightness-up mode, the light source drive unit 17 and the control unit (CPU) 24 control the duration of yellow light emission based on the LAMP_ENBL pulse. That is, in the brightness-up mode, the light source drive unit 17 and the control unit (CPU) 24 perform projection processing using yellow light, which has a relatively high brightness, instead of red light, which has a relatively low brightness.

[0092] Therefore, according to the first embodiment, a projection device 10 can be realized that can improve the brightness of the emitted light by using the brightness-up mode.

[0093] Furthermore, it enables brighter display in simple image projections, resulting in clearer image display.

[0094] [2] Second embodiment The second embodiment is an example of projection processing using three segments. In the second embodiment, in normal mode, projection processing is performed using three segments of red light, green light, and blue light, and in brightness-enhanced mode, projection processing is performed using three segments in which the red light is changed to yellow light, i.e., three segments of yellow light, green light, and blue light.

[0095] [2-1] Normal mode First, let's explain the operation of the normal mode. The normal mode is mode M2, which uses three segments. Mode M2 ​​performs projection processing using the three segments G, B, and R.

[0096] Figure 9 is a timing diagram illustrating the light emission process of the projection device 10 in normal mode. The angles G, B, and R are examples and can be set as appropriate according to the specifications.

[0097] Time t0 is the start timing of the frame. At time t0, the light source drive unit 17 turns on the semiconductor laser 31 and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits green light toward the mirror 20.

[0098] At time t1, the projection processing unit 16 generates the first LAMP_ENBL pulse. In response to the rising edge of the first LAMP_ENBL pulse, the light source drive unit 17 maintains the semiconductor laser 31 on and the LED 32 off. The phosphor wheel 35 transmits the blue light from the semiconductor laser 31. The light source unit 18 emits blue light toward the mirror 20.

[0099] At time t2, the projection processing unit 16 generates the second LAMP_ENBL pulse (first pulse). In response to the rising edge of the second LAMP_ENBL pulse, the light source drive unit 17 turns off the semiconductor laser 31 and turns on the LED 32. The light source unit 18 emits red light toward the mirror 20.

[0100] At time t3, the projection processing unit 16 generates the third LAMP_ENBL pulse. In response to the rising edge of the third LAMP_ENBL pulse, the light source drive unit 17 turns on the semiconductor laser 31 and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits the green light toward the mirror 20.

[0101] After three LAMP_ENBL pulses are generated, the index signal is activated. When the index signal is activated, the light source drive unit 17 clears the count value of the counter 28 to zero.

[0102] In this way, the projection device 10 emits green light, blue light, and red light in that order within one frame. Subsequently, the operation for one frame shown in Figure 9 is repeated.

[0103] [2-2] Brightness Boost Mode Next, the operation of the brightness-up mode will be explained. The brightness-up mode is the same as mode M3 mentioned above. In brightness-up mode, the brightness of the projection device 10 is increased by illuminating the yellow light, which has the highest brightness, instead of the red light, which has a relatively low brightness.

[0104] Figure 10 is a timing diagram illustrating the light emission process of the projection device 10 in the brightness-up mode. The angles G, B, and Y are examples and are based on, for example, the angles of the normal mode described above.

[0105] The emission processing of green and blue light is the same as in the normal mode described in Figure 9.

[0106] At time t2, the projection processing unit 16 generates the second LAMP_ENBL pulse (first pulse). In response to the rising edge of the second LAMP_ENBL pulse, the light source drive unit 17 maintains the semiconductor laser 31 on and turns on the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The LED 32 emits red light. The light source unit 18 emits yellow light toward the mirror 20 by mixing the third color light (green light in this embodiment) and the red light.

[0107] At time t3, the projection processing unit 16 generates the third LAMP_ENBL pulse. In response to the rising edge of the third LAMP_ENBL pulse, the light source drive unit 17 keeps the semiconductor laser 31 on and turns off the LED 32. The phosphor wheel 35 converts the blue light from the semiconductor laser 31 into green light. The light source unit 18 emits the green light toward the mirror 20.

[0108] After three LAMP_ENBL pulses are generated, the index signal is activated. When the index signal is activated, the light source drive unit 17 clears the count value of the counter 28 to zero.

[0109] In this way, the projection device 10 emits green light, blue light, and yellow light in that order within one frame. Subsequently, the operation for one frame shown in Figure 10 is repeated.

[0110] [2-3] Effects of the second embodiment As detailed above, in the second embodiment, the projection device 10 is newly equipped with a brightness-up mode for improving brightness. In the brightness-up mode, the light source drive unit 17 and the control unit (CPU) 24 perform projection processing using yellow light, which has a relatively high brightness, instead of red light, which has a relatively low brightness, based on the LAMP_ENBL pulse.

[0111] Therefore, according to the second embodiment, a projection device 10 capable of improving the brightness of emitted light can be realized by using the brightness-enhancing mode. Other effects are the same as in the first embodiment.

[0112] [3] Other examples In the above embodiment, yellow light is used to improve brightness, but the invention is not limited to this. For example, instead of yellow light, it is possible to use light of a color that is produced by mixing two colors and has a higher brightness than red light. For example, instead of yellow light, it is possible to use cyan or magenta light. In one embodiment, blue light may be used as the third color of light mixed with red light in the second embodiment.

[0113] In the above embodiment, the semiconductor laser 31 and LED 32 were switched on and off in response to the rising edge of the LAMP_ENBL pulse. However, the semiconductor laser 31 and LED 32 may also be switched on and off in response to the falling edge of the LAMP_ENBL pulse. In this case, the width of the LAMP_ENBL pulse is set to be shorter than the spoke period SP.

[0114] In the above embodiment, a case was described in which the light source unit 18 obtains blue and green light from a red LED as an independent light source and a blue laser via a phosphor wheel. However, the present invention is not limited to the above embodiment. For example, a color wheel and phosphors arranged outside the color wheel may be used instead of the phosphor wheel.

[0115] In this embodiment, a functional block may consist of hardware alone, software alone, or a combination thereof.

[0116] The functional configuration in this embodiment is realized by a processor that performs arithmetic processing. Processors that can be used in this embodiment include not only single-processor, multi-processor, and multi-core processors, but also combinations of these various processing units with processing circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays).

[0117] When a series of processes are executed by software, the programs that make up that software are installed on a computer or other device from a network or from a non-temporary computer-readable storage medium.

[0118] A computer may be a computer built into dedicated hardware. Alternatively, a computer may be a computer capable of performing various functions by installing various programs, such as a general-purpose personal computer.

[0119] Recording media containing such programs consist not only of removable media distributed separately from the main unit to the user to provide the program, but also of recording media provided to the user in a state where they are pre-installed in the main unit. Removable media consist of, for example, magnetic disks, optical disks, or magneto-optical disks. Optical disks consist of, for example, CD-ROMs (Compact Disk-Read Only Memory), DVDs (Digital Versatile Disks), Blu-ray® Discs, etc. Magneto-optical disks consist of, for example, MDs (Mini-Disks). Recording media provided to the user in a state where they are pre-installed in the main unit consist of, for example, semiconductor memory included in the storage unit on which the program is recorded.

[0120] The step of writing a program to be recorded on a recording medium includes not only processes that are performed chronologically in that order, but also processes that are not necessarily performed chronologically, but are executed in parallel or individually.

[0121] The present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention.

[0122] The invention described in the original claims of this application is listed below.

[0123] [Claim 1] A light source unit that emits multiple colors of light in a time-division manner and in a cyclical manner, Control unit and It is equipped with, The light source unit is capable of emitting light of a first color and light of a second color having a higher brightness than the first color. The control unit, Multiple pulses are generated to switch the color of the light emitted from the light source unit, Based on the above-mentioned plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the period for emitting the second color of light is made longer than the period for emitting the first color of light. Projection device.

[0124] [Claim 2] The control unit, Processing can be performed using the first mode and the second mode. The control unit, The interval between the first pulse and the second pulse in the second mode is controlled to be shorter than the interval between the first pulse and the second pulse in the first mode. The projection apparatus according to claim 1.

[0125] [Claim 3] The second pulse is located within a spoke period for switching the color of the light emitted from the light source unit where the first pulse is located. The projection apparatus according to claim 1 or 2.

[0126] [Claim 4] The light source unit emits the second color of light by mixing the first color of light with the third color of light. The projection apparatus according to any one of claims 1 to 3.

[0127] [Claim 5] A light source unit that emits multiple colors of light in a time-division manner and in a cyclical manner, Control unit and It is equipped with, The light source unit is capable of emitting light of a first color and light of a second color having a higher brightness than the first color. The control unit, A pulse is generated at each spoke period to switch the color of the light emitted from the light source unit. In the first mode, based on the first pulse among the pulses, the first color of light is emitted from the light source. In the second mode, based on the first pulse, the first color of light is mixed with the third color of light to emit the second color of light. Projection device.

[0128] [Claim 6] The previously mentioned first color of light is red light, The second color of light is yellow light. The projection apparatus according to any one of claims 1 to 5.

[0129] [Claim 7] The third color of light is green. The projection apparatus according to any one of claims 1 to 6.

[0130] [Claim 8] A projection method for a projection apparatus comprising a light source unit capable of cyclically emitting multiple colors of light in a time-division manner, and emitting a first color of light and a second color of light having a higher brightness than the first color, Multiple pulses are generated to switch the color of the light emitted from the light source unit, Based on the above-mentioned plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the period for emitting the second color of light is made longer than the period for emitting the first color of light. Projection method.

[0131] [Claim 9] A program executed by a computer built into a projection device that has a light source unit capable of emitting light of multiple colors in a time-division manner, and emitting light of a first color and light of a second color having a higher brightness than the first color, wherein the computer is controlled by Multiple pulses are generated to switch the color of the light emitted from the light source unit, A program that, based on a first pulse for emitting light of the first color, a second pulse for switching the emitted light from the first color to the second color, and a third pulse for switching the emitted light from the second color to the third color, functions to make the period for emitting the second color light longer than the period for emitting the first color light. [Explanation of Symbols]

[0132] 10…Projection device 11…Input / Output Connectors 12… Input / Output Interfaces 13... Bus 14…Image conversion 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…Speech Processing Unit 23...Speaker 24…CPU 25...Storage section 26...Operation unit 27…Power circuit 28... Counter 31… Semiconductor laser 32…LED 33...Miller 34… Dichroic mirror 35...Phosphor Wheel 36… Index Sensor 37…motor 38...Mirror 39...Miller 40… Dichroic mirror 41…Integrator 42...Mirror 50...Base material 51...Bearing 52…Transmission area 53…Reflection domain

Claims

1. A light source unit that emits multiple colors of light in a time-division manner and in a cyclical manner, Control unit and It is equipped with, The light source unit is capable of emitting light of a first color and light of a second color having a higher brightness than the first color. The control unit, Multiple pulses are generated to switch the color of the light emitted from the light source unit, Based on the above-mentioned plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the period for emitting the second color of light is made longer than the period for emitting the first color of light. The light source unit emits the second color of light by mixing the first color of light with the third color of light. Projection device.

2. The control unit, Processing can be performed using the first mode and the second mode. The control unit, The interval between the first pulse and the second pulse in the second mode is controlled to be shorter than the interval between the first pulse and the second pulse in the first mode. The projection apparatus according to claim 1.

3. The second pulse is located within a spoke period for switching the color of the light emitted from the light source unit where the first pulse is located. The projection apparatus according to claim 1 or 2.

4. A light source unit that emits multiple colors of light in a time-division manner and in a cyclical manner, Control unit and It is equipped with, The light source unit is capable of emitting light of a first color and light of a second color having a higher brightness than the first color. The control unit, A pulse is generated at each spoke period to switch the color of the light emitted from the light source unit. In the first mode, based on the first pulse among the pulses, the first color of light is emitted from the light source. In the second mode, based on the first pulse, the second color of light is emitted by mixing the first color of light with the third color of light. Projection device.

5. The first color of light mentioned above is red light, The second color of light is yellow light. The projection apparatus according to any one of claims 1 to 4.

6. The third color of light is green. The projection apparatus according to any one of claims 1 to 5.

7. A projection method for a projection apparatus comprising a light source unit capable of emitting multiple colors of light in a time-division manner, and emitting a first color of light and a second color of light having a higher brightness than the first color, Multiple pulses are generated to switch the color of the light emitted from the light source unit, Based on the above-mentioned plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the period for emitting the second color of light is made longer than the period for emitting the first color of light. The light source unit emits the second color of light by mixing the first color of light with the third color of light. Projection method.

8. A program executed by a computer built into a projection device having a light source unit that cyclically emits multiple colors of light in a time-division manner, and is capable of emitting a first color of light and a second color of light with higher brightness than the first color, wherein the computer is... Multiple pulses are generated to switch the color of the light emitted from the light source unit, Based on the above-mentioned plurality of pulses, a first pulse for emitting the first color of light, a second pulse for switching the emitted light from the first color of light to the second color of light, and a third pulse for switching the emitted light from the second color of light to the third color of light, the period for emitting the second color of light is made longer than the period for emitting the first color of light. The light source unit is programmed to function as a unit that emits light of the second color by mixing light of the first color with light of the third color.

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