JP2022017368A - Projection device, projection control device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection device, a projection control device, and a program capable of maintaining reproducibility of gradation.

SOLUTION: A projection device 10 includes: a semiconductor light-emitting element; a color wheel 201; a light source device 60 for emitting light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner; a display element 51; a projection optical system 220; a delay time setting unit 54 for shifting a start timing of a color mixing period in which first wavelength band light and second wavelength band light are mixed and emitted in a spoke period Tsp of a color wheel 201, which is a light emission switching time of the first wavelength band light and the second wavelength band light based on an index related to the brightness of light emitted from a light source device 60; and a light source driving unit 55 for emitting light based on a setting of the delay time setting unit 54.

SELECTED DRAWING: Figure 6

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a projection device, a projection control device and a program.

Conventionally, a projection device for driving a light source unit including a light emitting element that emits light of each color in a time-division manner has been disclosed. For example, in the projection device disclosed in Patent Document 1, a spoke period is set as a period during which each color light from the light source unit is switched. During the spoke period, each color light is mixed. By setting the components of the mixed color light during the spoke period in advance, it is possible to set a color mode for increasing the brightness or chromaticity of the image.

Japanese Unexamined Patent Publication No. 2012-155268

However, in the mixed color light during the spoke period, the amount of light emitted from each light emitting element may change due to a change in the drive current of the light emitting element depending on the color mode used. Then, in an image with a gradation, the gradation may be discontinuous.

In view of the above points, it is an object of the present invention to provide a projection device, a projection control device and a program capable of maintaining the reproducibility of gradation.

The projection device according to the present invention includes a semiconductor light emitting element and a color wheel, and has a light source unit that emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner, and a light source unit. A display element that is irradiated with light from a light source to form image light, a projection optical system that projects the image light emitted from the display element onto a projection target, and an index relating to the brightness of the light emitted from the light source unit. Based on this, the first wavelength band light and the second wavelength band light are mixed and emitted during the spoke period of the color wheel, which is the emission switching time between the first wavelength band light and the second wavelength band light. It is characterized by having a delay time setting unit for shifting the start timing of the color mixing period, and a light source driving unit for driving the light source unit based on the setting of the delay time setting unit.

The projection control device according to the present invention includes a semiconductor light emitting element and a color wheel, and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner. Based on the index related to the brightness, the first wavelength band light and the second wavelength band light in the spoke period of the color wheel, which is the emission switching timing of the first wavelength band light and the second wavelength band light, It is characterized by having a delay time setting unit that shifts the start timing of the color mixing period emitted by mixing colors, and a light source driving unit that drives the light source unit based on the setting of the delay time setting unit.

The program according to the present invention is a program executed by a computer, wherein the computer includes a semiconductor light emitting element and a color wheel, and time-divides light of a plurality of colors including first wavelength band light and second wavelength band light. Based on the index relating to the brightness of the light emitted from the light source unit emitted in, the first wavelength in the spoke period of the color wheel, which is the emission switching timing between the first wavelength band light and the second wavelength band light. A delay time setting unit that shifts the start timing of the color mixing period in which the band light and the second wavelength band light are mixed and emitted, and a light source driving unit that drives the light source unit based on the setting of the delay time setting unit. It is characterized by functioning as.

According to the present invention, it is possible to provide a projection device, a projection control device, and a program capable of maintaining the reproducibility of gradation.

It is a functional circuit block diagram of the projection apparatus which concerns on embodiment of this invention. It is a functional circuit block diagram which shows the details of the control part and the light source control circuit of the projection apparatus which concerns on embodiment of this invention. It is a plan view of the internal structure of the light source device in the projection device which concerns on embodiment of this invention. In the light source device of the projection device according to the embodiment of the present invention, (a) is a front schematic view of a fluorescent wheel, and (b) is a front schematic view of a color wheel. It is a timing chart diagram of the projection apparatus which concerns on embodiment of this invention. It is a figure which shows the rising waveform of the blue laser diode which concerns on embodiment of this invention, (a) shows the waveform before delay adjustment, (b) is set so that the change part of the waveform should be closer to the center part of a spoke period. (C) shows the waveform after delay adjustment. It is a flowchart which shows the delay adjustment in the projection apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of the projection device 10 (projection control device). The projection device 10 includes a control unit 38, an input / output interface 22, an image conversion unit 23, a display encoder 24, a display drive unit 26, and the like. Image signals of various standards input from the input / output connector unit 21 are converted into image signals of a predetermined format suitable for display by the image conversion unit 23 via the input / output interface 22 and the system bus (SB) by the projection control device. It is converted to be unified and output to the display encoder 24.

The control unit 38 controls the operation of each circuit in the projection device 10, and is a ROM that fixedly stores an operation program such as a CPU as an arithmetic unit and various settings, a RAM that is used as a work memory, and the like. It is composed of.

The display encoder 24 expands and stores the input image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display drive unit 26.

The display drive unit 26 drives the display element 51, which is a spatial light modulation element (SOM), at an appropriate frame rate corresponding to the image signal output from the display encoder 24.

The projection device 10 includes a light source device 60 that emits blue wavelength band light, green wavelength band light (first wavelength band light), and red wavelength band light (second wavelength band light). The emitted light emitted from the light source device 60 is applied to the display element 51 and is reflected by the display element 51 to form an image light. The reflected image light is projected onto a screen or the like via a projection optical system 220 described later.

The projection optical system 220 has a movable lens group. The movable lens group is driven by the lens motor 45 for zoom adjustment and focus adjustment.

The image compression / decompression unit 31 reads out the image data recorded on the memory card 32 at the time of reproduction, and decompresses the individual image data constituting the series of moving images in units of one frame. Further, the image compression / decompression unit 31 outputs the decompressed image data to the display encoder 24 via the image conversion unit 23, and enables display of a moving image or the like based on the image data stored in the memory card 32. Let the process be performed.

The key / indicator unit 37 is provided in the housing of the projection device 10. The operation signal from the key / indicator unit 37 is sent directly to the control unit 38. The key operation signal from the remote controller is received by the Ir receiving unit 35, demodulated by the Ir processing unit 36, and output to the control unit 38.

A voice processing unit 47 is connected to the control unit 38 via a system bus (SB). The voice processing unit 47 includes a sound source circuit such as a PCM sound source, converts voice data into analog in the projection mode and the reproduction mode, and drives the speaker 48 to emit loud sound.

The control unit 38 controls the light source control circuit 41. The light source control circuit 41 controls so that the light source light in a predetermined wavelength band required at the time of image generation is emitted from the light source device 60.

Further, the control unit 38 can cause the cooling fan drive control circuit 43 to detect the temperature by a plurality of temperature sensors provided in the light source device 60 or the like, and control the rotation speed of the cooling fan from the result of the temperature detection. The control unit 38 keeps the cooling fan rotating even after the power of the projection device 10 is turned off by a timer or the like in the cooling fan drive control circuit 43, or the power supply of the projection device 10 is supplied depending on the result of temperature detection by the temperature sensor. Controls such as turning it off can also be performed.

Further, as shown in FIG. 2, the control unit 38 of the projection control device, which is the projection device 10 in the present embodiment, includes a timing setting unit 53, a delay time setting unit 54, and a light source driving unit 55. Further, the light source control circuit 41 includes a detection unit 56 that detects information indicating the amount of light of each color light emitted from the projection optical system 220. Details of these will be described later.

Next, the internal structure of the light source device 60 in the projection device 10 will be described with reference to FIG. In the following description, the left and right in the projection device 10 indicate the left-right direction with respect to the projection direction, and the front-back means the front-back direction with respect to the screen side direction of the projection device 10 and the traveling direction of the light flux. ..

The light source device 60 includes an excitation light irradiation device 70 which is a light source of blue wavelength band light and is also an excitation light source, a green light source device 80 which is a light source of green wavelength band light, and a red light source device which is a light source of red wavelength band light. A 120 and a color wheel device 200 are provided. The green light source device 80 includes an excitation light irradiation device 70 and a fluorescence wheel device 100.

A light guide optical system 140 that guides light in each color wavelength band is arranged in the light source device 60. The light guide optical system 140 guides the light emitted from the excitation light irradiation device 70, the green light source device 80, and the red light source device 120 to the light source optical system 170. The excitation light irradiation device 70 includes a blue laser diode 71, a condenser lens 77, 78, and a diffuser plate 79, which are a plurality of semiconductor light emitting elements.

On the optical axis of each blue laser diode 71, a collimator lens 73 that converts light into parallel light is arranged so as to enhance the directivity of the light emitted from the blue laser diode 71. The condenser lens 77 and the condenser lens 78 reduce the light beam emitted from the blue laser diode 71 in one direction and emit it to the diffuser plate 79. The diffuser plate 79 diffuses and transmits the incident blue wavelength band light to the first dichroic mirror 141 arranged on the fluorescence wheel 101 side.

The fluorescence wheel device 100 is arranged on the optical path of the excitation light emitted from the excitation light irradiation device 70. The fluorescent wheel device 100 includes a fluorescent wheel 101, a motor 110, a condenser lens group 111, and a condenser lens 115. The fluorescence wheel 101 is arranged so as to be orthogonal to the optical axis of the emitted light from the excitation light irradiation device 70 so that the upper position of the fluorescence wheel 101 is the irradiation position S (see FIG. 3A). The motor 110 arranged below the condenser lens group 111 and the condenser lens 115 rotationally drives the fluorescence wheel 101.

As shown in FIG. 4A, the fluorescent wheel 101 is formed in a disk shape, and the bearing 112 at the center is fixed to the shaft portion of the motor 110 and rotated by the drive of the motor 110. The fluorescence wheel 101 has a fluorescence emission region 310 and a transmission region 320 arranged side by side in the circumferential direction. The base material of the fluorescent wheel 101 can be formed of a metal base material such as copper or aluminum. The surface of this base material on the side of the excitation light irradiation device 70 is mirror-processed by silver vapor deposition or the like. In the fluorescence emission region 310, a green phosphor layer formed on the mirrored surface is formed. The fluorescence emission region 310 receives blue wavelength band light as excitation light from the excitation light irradiation device 70, and emits fluorescence in the green wavelength band in all directions. A part of the fluorescence is directly emitted to the condenser lens 111, and the other part is reflected by the reflecting surface of the fluorescence wheel 101 and then emitted to the condenser lens 111.

Further, the transmission region 320 of the fluorescent wheel 101 can be formed by fitting a transparent base material having translucency into a cutout portion formed in the base material of the fluorescent wheel 101. The transparent substrate is formed of a transparent material such as glass or resin. Further, the transparent substrate may be provided with a diffusion layer on the surface on the side irradiated with the blue wavelength band light or on the opposite side thereof. The diffusion layer can be provided, for example, by forming fine irregularities by sandblasting or the like on the surface of the transparent base material. The blue wavelength band light from the excitation light irradiation device 70 incident on the transmission region 320 transmits or diffuses through the transmission region 320 and is incident on the condenser lens 115.

Returning to FIG. 3, the condenser lens group 111 condenses the light bundle of the blue wavelength band light emitted from the excitation light irradiation device 70 on the fluorescence wheel 101 and also condenses the fluorescence emitted from the fluorescence wheel 101. The condenser lens 115 collects a bundle of light rays emitted from the fluorescent wheel 101.

The red light source device 120 collects the red light emitting diode 121, which is a semiconductor light emitting element arranged so that the blue laser diode 71 and the optical axis of the emitted light are parallel to each other, and the red wavelength band light emitted from the red light emitting diode 121. It includes a light condensing lens group 125 and. In the red light source device 120, the optical axis of the red wavelength band light emitted from the red light emitting diode 121 intersects with the optical axis of the green wavelength band light emitted from the fluorescence wheel 101 and reflected by the first dichroic mirror 141. Is placed in.

The light guide optical system 140 converts the optical axis of the first dichroic mirror 141, the second dichroic mirror 142, the third dichroic mirror 143, the condensing lens 145, 146, 147 for condensing the light beam bundle, and each light beam bundle. It is composed of a reflection mirror 144 or the like having the same optical axis. Hereinafter, each member will be described.

The first dichroic mirror 141 is arranged at a position between the diffuser plate 79 and the condenser lens group 111. The first dichroic mirror 141 transmits the blue wavelength band light to the condenser lens group 111 side and reflects the green wavelength band light in the direction of the condenser lens 145 to convert the optical axis by 90 degrees.

The second dichroic mirror 142 is a synthesis means for synthesizing green wavelength band light and red wavelength band light on the same optical axis, reflects green wavelength band light, and transmits red wavelength band light. The green wavelength band light reflected by the first dichroic mirror 141 is collected by the condenser lens 145 and incident on the second dichroic mirror 142.

The green wavelength band light reflected by the second dichroic mirror 142 is condensed by the condenser lens 146 and incident on the third dichroic mirror 143 arranged on the exit side of the condenser lens 146. The third dichroic mirror 143 reflects the red wavelength band light and the green wavelength band light and transmits the blue wavelength band light. Therefore, the third dichroic mirror 143 reflects the red wavelength band light and the green wavelength band light focused by the condenser lens 146 to the condenser lens 173 to guide the red wavelength band light and the green wavelength band light. ..

Further, when the irradiation position S of the blue wavelength band light in the fluorescence wheel 101 is the transmission region 320 (see FIG. 4A), the blue wavelength band light emitted from the blue laser diode 71 is transmitted or diffused through the fluorescence wheel 101. It is transmitted, collected by the condenser lens 115, and then guided to the reflection mirror 144. The reflection mirror 144 is arranged on the optical axis of the blue wavelength band light transmitted or diffused through the fluorescence wheel 101. The reflection mirror 144 reflects the blue wavelength band light, converts the optical axis by 90 degrees, and guides the light to the condenser lens 147. The third dichroic mirror 143 transmits the blue wavelength band light focused by the condenser lens 147 and guides the light toward the condenser lens 173.

The light source optical system 170 includes a condenser lens 173, a light tunnel 175, a condenser lens 178, an optical axis conversion mirror 181 and a condenser lens 183, an irradiation mirror 185, and a condenser lens 195. Since the condenser lens 195 emits the image light emitted from the display element 51 arranged behind the condenser lens 195 toward the projection optical system 220, it is also a part of the projection optical system 220.

The condenser lens 173 is arranged on the third dichroic mirror 143 side of the light tunnel 175. The condenser lens 173 collects the green wavelength band light, the blue wavelength band light, and the red wavelength band light guided from the third dichroic mirror 143. Each color wavelength band light collected by the condenser lens 173 is applied to the color wheel 201 of the color wheel device 200.

The color wheel device 200 includes a color wheel 201 and a motor 210 that rotationally drives the color wheel 201. The color wheel device 200 is arranged between the condenser lens 173 and the light tunnel 175 so that the optical axis of the light beam emitted from the condenser lens 173 and the irradiation surface on the color wheel 201 are orthogonal to each other.

As shown in FIG. 4B, the color wheel 201 is formed in a disk shape, and the bearing 113 at the center is fixed to the shaft portion of the motor 210 and is rotationally driven by the motor 210. The color wheel 201 has an all-color transmission region 410 and a blue-red transmission region 420 arranged side by side in the circumferential direction. The all-color transmission region 410 is formed of transparent glass or a resin plate, and can transmit light in all wavelength bands including blue wavelength band light, green wavelength band light, and red wavelength band light. Further, the blue-red transmission region 420 is formed by a color filter and can transmit blue wavelength band light and red wavelength band light. The blue wavelength band light, the green wavelength band light, and the red wavelength band light incident on the color wheel 201 pass through the all-color transmission region 410 or the blue-red transmission region 420 and are dimmed, and then enter the light tunnel 175 in FIG. It is guided toward. The ray bundle incident on the light tunnel 175 becomes a ray bundle having a uniform intensity distribution in the light tunnel 175.

A condenser lens 178 is arranged on the optical axis behind the light tunnel 175. An optical axis conversion mirror 181 is arranged further behind the condenser lens 178. The light beam bundle emitted from the exit port of the light tunnel 175 is focused by the condenser lens 178 and then reflected by the optical axis conversion mirror 181 toward the left panel 15.

The light beam bundle reflected by the optical axis conversion mirror 181 is focused by the condenser lens 183, and then is irradiated to the display element 51, which is a DMD, by the irradiation mirror 185 at a predetermined angle via the condenser lens 195.

The light source light applied to the image forming surface of the display element 51 by the light source optical system 170 is reflected by the image forming surface of the display element 51 and projected onto the screen as projected light via the projection optical system 220. Here, the projection optical system 220 is composed of a condenser lens 195, a movable lens group and a fixed lens group provided in the lens barrel 230. The lens barrel 230 is a varifocal lens, and is formed so that zoom adjustment and focus adjustment are possible. The movable lens group is formed so as to be movable automatically by the lens motor 45 or manually by the projection image adjusting unit 15a.

By configuring the projection device 10 in this way, when the fluorescent wheel 101 and the color wheel 201 are rotated synchronously and light is emitted from the excitation light irradiation device 70 and the red light source device 120 at appropriate timings, green, blue, and red colors are emitted. Each wavelength band light is incident on the condenser lens 173 via the light guide optical system 140, and is incident on the display element 51 via the light source optical system 170. Therefore, the display element 51 can project a color image on the screen by displaying the light of each color in a time-division manner according to the data.

FIG. 5 shows red in synchronization with the rising timing tap (tup1, tup2, tup3) of the segment switching timing pulse TP from the control unit 38 during the unit image frame T (T ₀ , T ₁ , T ₂ ...) Period. This is an example of a time chart in which the light source device 60 emits a synthetic color light source light by switching each segment of the wavelength band light (R), the green wavelength band light (G), and the blue wavelength band light (B). In FIG. 5, the red light source device 120 (red light emitting diode 121) is an R-LED, the excitation light irradiation device 70 (blue laser diode 71) is a B-LD, and the fluorescence light emitting region 310 of the fluorescence wheel device 100 (fluorescence wheel 101) is. G-FW, the transmission region 320 is indicated by B-FW, the blue-red transmission region 420 of the color wheel device 200 (color wheel 201) is indicated by B / R-CW, and the all-color transmission region 410 is indicated by ALL-CW. Here, the red light source device 120 (R-LED), the excitation light irradiation device 70 (B-LD), the fluorescence emission region 310 (G-FW), the transmission region 320 (B-FW), and the blue-red transmission region 420 (B). The heights in the R-CW) and the all-color transmission region 410 (ALL-CW) schematically indicate the amount of light emitted by each.

Further, a fixed time is set as the spoke period Tsp from the rising timing tap (tup1, tap2, tap3) of the segment switching timing pulse TP. The timing up and the spoke period Tsp are set by the timing setting unit 53. In the present embodiment, the mixed color light is set to be emitted during the spoke period Tsp.

For example, in the period T ₁₁ , the red light source device 120 (R-LED) that has been emitting light in the previous period T ₀ starts to turn off at the timing of the rising timing up 1 of the segment switching timing pulse TP. Further, the emission of the blue wavelength band light is started from the excitation light irradiation device 70 (B-LD). As a result, the fluorescence emission region 310 receives the blue wavelength band light as the excitation light from the excitation light irradiation device 70, and the emission of the fluorescence in the green wavelength band is started. On the other hand, the color wheel device 200 switches from the blue-red transmission region 420 (BRCW) to the all-color transmission region 410 (ALL-CW). The emitted light of the excitation light irradiation device 70 (B-LD) irradiates the fluorescence emission region 310 (G-FW), and the fluorescence of the green wavelength band light is emitted. However, the red wavelength band light (the red wavelength band light from the red light source device 120 (R-LED) and the green wavelength band light from the fluorescence emission region 310 (G-FW) are the blue-red transmission region 420 (BR-). The irradiation spot of the light source light of the red component light transmitted through CW) extends from the blue-red transmission region 420 (BRCW) to the all-color transmission region 410 (ALL-CW) and gradually becomes red. The ratio of wavelength band light changes. Therefore, the red wavelength band light (the red wavelength band light from the red light source device 120 (R-LED) and the green wavelength band light from the fluorescence emission region 310 (G-FW) are the blue-red transmission region 420 (BR-). The amount of light of the red component light transmitted through CW) is reduced, and the amount of light of the green wavelength band light transmitted through the all-color transmission region 410 (ALL-CW) is increased. Therefore, the spoke period Tsp of the period T ₁₁ is a color mixing period in which the red wavelength band light and the green wavelength band light are mixed and the yellow wavelength band light (Y) is emitted. When the spoke period of the yellow wavelength band light (Y) is 6 degrees, it is desirable that the light amount of the red light source device 120 (R-LED) at the time of 3 degrees is half the value at the time of lighting. Then, after the spoke period Tsp of the period T ₁₁ has elapsed, the red light source device 120 (R-LED) is completely turned off, and the color wheel 201 is transferred from the blue-red transmission region 420 (BRCW) to the all-color transmission region 410. It completely switches to (ALL-CW). Then, the green wavelength band light (G) is emitted from the light source device 60.

_In the period T12, the drive current value of the excitation light irradiation device 70 (B-LD) is increased at the timing of the rising timing up2, and the blue wavelength band light emitted from the excitation light irradiation device 70 (B-LD) is used. The amount of light is increased. On the other hand, the fluorescence wheel 101 switches from the fluorescence emission region 310 (G-FW) to the transmission region 320 (B-FW). Therefore, the spoke period _Tsp of the period T12 is a color mixing period in which the blue wavelength band light and the green wavelength band light are mixed and the cyan wavelength band light (CY) is emitted. After the spoke period _Tsp of the period T12 elapses, the blue wavelength band light (B) is emitted. The color wheel 201 has a blue-red transmission region 420 (BR-) from the all-color transmission region 410 (ALL-CW) during the period when the blue wavelength band light (B) is emitted (that is, during the period _T12 ). Switch to CW).

In the period T13, the red light source device 120 (R-LED) starts to light at the timing of the rising timing _up3 . On the other hand, the excitation light irradiation device 70 (B-LD) starts to go out. Therefore, _in the spoke period Tsp of the period T13, the red wavelength band light (red wavelength band light from the red light source device 120 (R-LED)) and the blue wavelength band light transmitted through the transmission region 320 (B-FW) are used. , Are mixed and the magenda color wavelength band light (MG) is emitted, and the color mixing period is set. After the spoke period _Tsp of the period T13 elapses, the red wavelength band light (R) is emitted.

In the time chart of FIG. 5, the current value while the excitation light irradiation device 70 is irradiating the fluorescence emission region 310 is decreased, but the current value while irradiating the fluorescence emission region 310 is increased. It may be set to lower the current value while transmitting through the transmission region 320.

The projection device 10 can be set to a “brightness-oriented” color mode for brightening the projected light by using, for example, the yellow wavelength band light (Y) of the spoke period _Tsp in the period T11. Further, for example, if the timing of switching from the all-color transmission region 410 (ALL-CW) of the period T12 to the blue-red transmission region 420 (BR-CW) is set to the timing _tap3 , the blue wavelength band light is transmitted to the all-color transmission region 410. It is also possible to set a "color-oriented mode" in which only (ALL-CW) is transmitted and a long emission period of red wavelength band light is taken. In addition, various color modes can be set by adjusting the amount of light by adjusting the drive current value of the blue laser diode 71 and the red light emitting diode 121.

Here, the amount of light of a semiconductor light emitting device such as the red light emitting diode 121 or the blue laser diode 71 gradually increases or decreases when the light emitting element is lit, the driving current is increased, or when the light is turned off or the driving current is decreased. This is because these semiconductor light emitting devices emit light with an amount of light corresponding to the current value, but have the characteristic of current rising (current falling) until the current value reaches the target current value and stabilizes. ..

6 (a) to 6 (c) schematically show an example of the rising waveform (light source current waveform) of the blue laser diode 71. In FIG. 5, such a rising waveform of the blue laser diode 71 is obtained by the rising timing _tap1 in the period T11 in which the emission of the blue wavelength band light is started from the excitation light irradiation device 70 (B-LD), or the excitation light irradiation device. The state seen in the rise timing _up2 at T12 during the period in which the drive current value of 70 (B-LD) is increased and the amount of light of the blue wavelength band light emitted from the excitation light irradiation device 70 (B-LD) is increased. Is.

The vertical axis represents the current value of the current driving the blue laser diode 71, and the horizontal axis represents time (spoke period Tsp). As shown in FIG. 6A, the blue laser diode 71 is represented by the changing portions I ₁₁ , I ₂₁ , and I ₃₁ in which the current values change until the target current values I ₁₂ , I ₂₂ , and I ₃₂ are reached. Has waveform characteristics. 6 (a) to 6 (c) show current waveforms I ₁ , I ₂ , and I ₃ corresponding to various color modes, and the current values are used as the target current values of the respective current waveforms I ₁ , I ₂ , and I ₃ . Three target current values I ₁₂ , I ₂₂ , and I ₃₂ are shown in descending order of.

The amount of light of the blue laser diode 71 is calculated by the current value and the time. The amount of light is calculated by the detection unit 56 detecting the current value of the blue laser diode 71. Therefore, as shown in FIG. 6A, when the current value fluctuates due to the change in the color mode, the amount of light in the spoke period Tsp changes. Then, when the projected image emitted via the projection optical system 220 has a gradation, discontinuous points may be seen in the gradation. Therefore, by adjusting the rising (or falling) timing of the current value for each color mode in which the current value fluctuates, that is, by setting the delay time of the light emission timing (delay adjustment), the amount of light changes in the spoke period Tsp. The ratio was made uniform so that the reproducibility of gradation could be maintained even if the color mode was changed.

The delay adjustment is performed according to the flowchart of FIG.
Step S001; When the delay adjustment is started, the delay time setting unit 54 first divides the spoke period Tsp into three as shown in FIG. 6A. Here, the period Tsp1, Tsp2, and Tsp3 are divided into three. For example, when the spoke period Tsp is set at 17 degrees, it is divided into Tsp1 = 6 degrees, Tsp2 = 6 degrees, and Tsp3 = 7 degrees.

Step S002; Next, an image having a gradation is projected on the screen via the projection optical system 220, and the gradation is visually confirmed.
Step S003, Step S004; When the gradation is unnaturally continuous, the delayed time setting unit 54 changes the divided spoke periods Tsp1, Tsp2, and Tsp3 as shown in FIG. 6B. , The color of the spoke period Tsp is set so that the changing portions I ₁₁ , I ₂₁ , and I ₃₁ of the current waveform are closer to the central part of the spoke period Tsp (that is, the period Tsp 2).

Step S005; The delay time setting unit 54 mixes and emits the red wavelength band light and the green wavelength band light in the delay time setting (that is, in the spoke period Tsp of the color wheel 201) between the minimum and maximum currents. Shift the start timing of the color mixing period). For example, in the example of FIG. 6C, the current waveform I ₁ having the highest target current value I ₁₂ has a delay time of Δt 1, and the current waveform I ₂ having an intermediate target current value I ₂₂ has a delay time of Δt 2. The current waveform I ₃ having the lowest current value I ₃₂ sets the delay time to Δt3.

In this way, as shown in FIG. 6 (c), the current waveforms I ₁ , I ₂ , I ₃ over the period Tsp 1 to the period Tsp 3 regardless of the height of the target current values I ₁₂ , I ₂₂ , and I ₃₂ . The rate of change in the amount of light can be made substantially constant. Then, the light source driving unit 55 drives the light source device 60 (light source unit) via the light source control circuit 41 based on the settings of the timing setting unit 53 and the delay time setting unit 54. Therefore, the image projected in this way maintains the reproducibility of gradation even if the color mode is changed.

In the present embodiment, the detection unit 56 measures the current value of the blue laser diode 71 to detect information indicating the amount of blue light emitted from the projection optical system 220 during the spoke period Tsp. It is not limited, and may be, for example, a detection unit provided with an illuminance sensor to measure the illuminance of the projected image and detect information indicating the amount of light of each color light. Further, in the present embodiment, the delay adjustment for the blue laser diode 71 has been described, but the delay adjustment for the red light emitting diode 121 can also be performed.

Further, the delay time setting between the minimum and maximum currents by the delay time setting unit 54 can be a look-up table stored in a storage unit such as an S-RAM connected to the control unit 38.

As described above, according to the embodiment of the present invention, the projection device 10 includes the excitation light irradiation device 70 (blue laser diode 71) and the color wheel device 200 (color wheel 201), and the red wavelength band light from the red light source device 120. From the light source device 60, which is a light source unit that emits light of a plurality of colors including (first wavelength band light) and green wavelength band light (second wavelength band light) from the fluorescent wheel device 100, and the light source device 60. Based on the index related to the brightness of the emitted light, the red wavelength band light and the green wavelength band light are mixed in the spoke period Tsp of the color wheel 201, which is the emission switching time between the red wavelength band light and the green wavelength band light. A delay time setting unit 54 that shifts the start timing of the color mixing period emitted from the light source and a light source drive unit 55 that drives the light source device 60 based on the setting of the delay time setting unit 54 are provided. This makes it possible to provide a projection device 10 capable of maintaining gradation reproducibility even when the color mode is changed.

Further, the spoke period Tsp is divided into three parts. Thereby, the spoke period Tsp can be changed by switching the delay adjustment in conjunction with the color mode.

Further, in the delay time setting unit 54, the change units I ₁₁ , I ₂₁ , and I ₃₁ of the information indicating the amount of light of each color light (that is, the index related to the brightness of the light) move to the central portion of the spoke period Tsp divided into three. In this way, the delay time (shifting the start timing of the color mixing period) is set. As a result, it is possible to reduce the man-hours for calibration during the spoke period (period Tsp3) in which the blue laser diode 71 does not fluctuate.

Further, the index regarding the brightness of light includes the drive current or temperature of the blue laser diode 71. As a result, the reproducibility of gradation can be maintained even if the drive current value of the blue laser diode 71 or the temperature due to the use of the blue laser diode 71 changes.

Further, the delay time setting unit 54 sets the switching timing of the plurality of lights emitted by the light source device 60 for each of the plurality of color modes. As a result, the reproducibility of gradation can be maintained even in the color mode in which the switching timing of light changes.

Further, the color mode includes a brightness-oriented mode in which the brightness of the projected image is emphasized and a color-oriented mode in which the color tone of the projected image is emphasized. As a result, a clear projected image can be obtained even in a bright room, and a projected image suitable for viewing a movie or the like can be obtained.

Further, the start timing of the color mixing period is set between the minimum current value and the maximum current value of the drive current of the blue laser diode 71. As a result, it is possible to provide the projection device 10 in which the gradation does not fluctuate depending on the value of the current flowing through the light source, and the range of the current value that can maintain the reproducibility of the gradation is wider than before.

The delay time of the light emission timing in the light source unit set by the delay time setting unit is based on the index related to brightness, but the index related to brightness is not based on a plurality of color modes, but the brightness set by the user. It may be based on the sword.
Further, if the delay time of the light emission timing in the light source unit set by the delay time setting unit is determined based on an index related to brightness, information indicating the amount of light of each color light (blue laser diode 71 which is a semiconductor light emitting element). It may be set based on other than the current value of the drive current and the brightness set by the user.

For example, since the semiconductor light emitting device generates heat and changes in temperature with the use of the projection device, the delay time may be set according to the temperature of the semiconductor light emitting device. In this way, the delay time setting unit can set the delay time every predetermined time (for example, every 100 μs) based on various indicators related to brightness.

Further, the control unit 38 of the projection device 10, which is a projection control device, includes a delay time setting unit 54 and a light source drive unit 55. Then, the control unit 38 functions as a delay time setting unit 54 and a light source drive unit 55 by a program stored in a storage unit such as an S-RAM connected to the control unit 38. This makes it possible to provide a projection control device and a program that can maintain the reproducibility of gradation even if the color mode is changed.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

The inventions described in the first claims of the present application are described below.
[1] A light source unit provided with a semiconductor light emitting element and a color wheel and emitting light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner.
A display element that is irradiated with light from the light source to form image light,
A projection optical system that projects the image light emitted from the display element onto a projection target,
Based on the index relating to the brightness of the light emitted from the light source unit, the first wavelength band light in the spoke period of the color wheel, which is the emission switching timing between the first wavelength band light and the second wavelength band light. And the delay time setting unit that shifts the start timing of the color mixing period in which the second wavelength band light is mixed and emitted.
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A projection device characterized by having.
[2] The projection device according to the above [1], wherein the spoke period is divided into three parts.
[3] The delay time setting unit is characterized in that the start timing of the color mixing period is set so that the change portion of the index relating to the brightness of the light is closer to the central portion of the spoke period divided into three. The projection device according to the above [2].
[4] The projection device according to any one of the above [1] to the above [3], wherein the index relating to the brightness of the light includes a driving current or a temperature of the semiconductor light emitting device.
[5] The description according to any one of the above [1] to the above [4], wherein the delay time setting unit sets the switching timing of the light of the plurality of colors emitted by the light source unit for each of the plurality of color modes. Projection device.
[6] The projection device according to the above [5], wherein the color mode includes a brightness mode in which the brightness of the projected image is emphasized and a color-oriented mode in which the color tone of the projected image is emphasized.
[7] The projection device according to the above [4], wherein the setting of the start timing of the color mixing period is performed between the minimum current value and the maximum current value of the drive current.
[8] Based on an index related to the brightness of light emitted from a light source unit that includes a semiconductor light emitting element and a color wheel and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner. Therefore, the first wavelength band light and the second wavelength band light are mixed and emitted during the spoke period of the color wheel, which is the emission switching time between the first wavelength band light and the second wavelength band light. A delay time setting unit that shifts the start timing of the color mixing period,
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A projection control device characterized by having.
[9] A program executed by a computer, wherein the computer is used.
The above is based on an index relating to the brightness of light emitted from a light source unit that includes a semiconductor light emitting element and a color wheel and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner. The color mixing period in which the first wavelength band light and the second wavelength band light are mixed and emitted in the spoke period of the color wheel, which is the emission switching time between the first wavelength band light and the second wavelength band light. A delay time setting unit that shifts the start timing,
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A program characterized by functioning as.

10 Projection device 15 Left panel 15a Projection image adjustment unit 21 Input / output connector unit 22 Input / output interface 23 Image conversion unit 24 Display encoder 25 Video RAM
26 Display drive 31 Image compression / decompression 32 Memory card 35 Ir receiver 36 Ir processing 37 Key / indicator 38 Control 41 Light source control circuit 43 Cooling fan drive control circuit 45 Lens motor 47 Voice processing 48 Speaker 51 Display Element 53 Timing setting unit 54 Delay time setting unit 55 Light source drive unit 56 Detection unit 60 Light source device 70 Excitation light irradiation device 71 Blue laser diode 73 Collimeter lens 77 Condensing lens 78 Condensing lens 79 Diffusing plate 80 Green light source device 100 Fluorescent wheel Device 101 Fluorescent wheel 110 Motor 111 Condensing lens group 111 Condensing lens 112 Bearing 113 Bearing 115 Condensing lens 120 Red light source device 121 Red light emitting diode 125 Condensing lens group 140 Light guide optical system 141 First dichroic mirror 142 Second dichroic Mirror 143 Third dichroic mirror 144 Reflective mirror 145 Condensing lens 146 Condensing lens 147 Condensing lens 170 Light source Optical system 173 Condensing lens 175 Light tunnel 178 Condensing lens 181 Optical axis conversion mirror 183 Condensing lens 185 Irradiation mirror 195 Condenser Lens 200 Color wheel device 201 Color wheel 210 Motor 220 Projection optical system 230 Lens lens barrel 310 Fluorescent emission area 320 Transmission area 410 All color transmission area 420 Blue-red transmission area

Claims (9)

A light source unit that includes a semiconductor light emitting device and a color wheel and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner.
A display element that is irradiated with light from the light source to form image light,
A projection optical system that projects the image light emitted from the display element onto a projection target,
Based on the index relating to the brightness of the light emitted from the light source unit, the first wavelength band light in the spoke period of the color wheel, which is the emission switching timing between the first wavelength band light and the second wavelength band light. And the delay time setting unit that shifts the start timing of the color mixing period in which the second wavelength band light is mixed and emitted.
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A projection device characterized by having. The projection device according to claim 1, wherein the spoke period is divided into three parts. 2. The delay time setting unit is characterized in that the start timing of the color mixing period is set so that the change portion of the index relating to the brightness of the light is closer to the central portion of the spoke period divided into three. The projection device described in. The projection device according to any one of claims 1 to 3, wherein the index relating to the brightness of the light includes a driving current or a temperature of the semiconductor light emitting device. The projection device according to any one of claims 1 to 4, wherein the delay time setting unit sets switching timings of light of a plurality of colors emitted by the light source unit for each of a plurality of color modes. The projection device according to claim 5, wherein the color mode includes a brightness mode in which the brightness of the projected image is emphasized and a color-oriented mode in which the color tone of the projected image is emphasized. The projection device according to claim 4, wherein the setting of the start timing of the color mixing period is performed between the minimum current value and the maximum current value of the drive current. The above is based on an index relating to the brightness of light emitted from a light source unit that includes a semiconductor light emitting element and a color wheel and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner. The color mixing period in which the first wavelength band light and the second wavelength band light are mixed and emitted in the spoke period of the color wheel, which is the emission switching time between the first wavelength band light and the second wavelength band light. A delay time setting unit that shifts the start timing,
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A projection control device characterized by having. A program executed by a computer, the computer
The above is based on an index relating to the brightness of light emitted from a light source unit that includes a semiconductor light emitting element and a color wheel and emits light of a plurality of colors including first wavelength band light and second wavelength band light in a time-divided manner. The color mixing period in which the first wavelength band light and the second wavelength band light are mixed and emitted in the spoke period of the color wheel, which is the emission switching time between the first wavelength band light and the second wavelength band light. A delay time setting unit that shifts the start timing,
A light source driving unit that drives the light source unit based on the setting of the delay time setting unit,
A program characterized by functioning as.

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