JP6234020B2 - Projector, projector control method and program - Google Patents

Description

  The present invention relates to a projection apparatus that projects an image of a hold-type display device such as a liquid crystal panel by causing a light source to emit light.

Conventionally, the projection apparatus performs a hold-type display. The hold-type display refers to a display that continuously displays the same image at a frame time of 16 ms with a frame frequency of 60 Hz.
When a moving image is displayed on a direct-view display device such as a television, if the hold-type display is performed, the moving image appears blurred. In order to solve the problem, there is one that controls lighting of the backlight. For example, the use of a technique for increasing the black insertion time called black insertion can improve the cut-off of moving images. However, when the black insertion time is long, an image with a frame frequency of 60 Hz is displayed with short light emission, which causes a problem that flicker occurs.

For example, Patent Document 2 discloses a display device that emits light with a bright original image and a dark intermediate image. In such a display device, although the above-described problems can be reduced to some extent, an image may be disturbed when an intermediate image generation error occurs.
Further, for example, Patent Literature 3 discloses a video display device that performs control to extend the lighting time of a backlight in accordance with necessary luminance.
Further, for example, Patent Document 4 discloses a display panel that performs control so as to extend the lighting time of the backlight in a period close to the center in accordance with necessary luminance.

JP 2011-28107 A JP 2008-70838 A JP 2002-215111 A JP 2009-251069 A

  Patent Document 1 discloses a hold-type image display device that emits light by switching light emission luminance between light and dark. Such a hold-type image display device can reduce the above-described problems. However, when an image with a frame frequency of 60 Hz is displayed with short light emission, flicker occurs, and when the light is emitted twice in one frame in order to prevent the occurrence of flicker, the moving image appears double. .

Also, as in Patent Documents 1 and 2, if the image is made up of two types of light and dark, flicker occurs due to the 60 Hz component in addition to the 120 Hz component. Therefore, if the light and dark difference is increased, the 60 Hz component increases and the flicker becomes stronger. It becomes difficult to see. Therefore, there is a limit to the difference between light and dark. In addition, a phenomenon in which the periphery of the displayed object appears to flicker due to the difference in shape between the original image and the intermediate image.
Further, as in Patent Documents 3 and 4, when light is emitted for a long time in order to brighten an image, tailing called moving image blurring is strongly generated.

  When a moving image is displayed on the projection device, motion blur and flicker occur as in the direct-view display device. However, since the above-described technique is a technique related to a direct-view display apparatus, it is difficult to apply the technique to a projection apparatus as it is.

  The present invention has been made in view of the above-described problems, and an object thereof is to reduce the occurrence of flicker and motion blur in a projection apparatus that projects an image on a display unit by emitting light. To do.

The projection device of the present invention is a projection device that displays an image by causing a light source to emit light, and includes an input unit that inputs image data, a gradation value indicated by the image data input by the input unit, and a plurality of gradation values Among the maximum light flux values set to different values in advance for each image projection mode, the maximum light flux value corresponding to the image projection mode selected as the image projection mode to be applied to the projection device from the plurality of image projection modes. Evaluation means for determining flicker information indicating ease of perception of flicker based on the evaluation, and the number of times the light source emits light within a time corresponding to an image of one frame corresponding to the image data input by the input means. and a control means for controlling to determine on the basis of the flicker information determined based on the maximum light flux value and the gradation value by means And wherein the door.

  According to the present invention, it has been made in view of the above-described problems, and it is possible to reduce the occurrence of flicker and moving image blur in a projection apparatus that projects an image on a display unit by emitting light. it can.

It is a figure which shows schematic structure of the projection apparatus of 1st Embodiment. It is a figure which shows the internal structure of the projection apparatus of 1st Embodiment. It is a figure which shows the light emission state by 1st Embodiment. It is a figure for demonstrating the experiment of the relationship between the brightness | luminance of a display patch, and the subjective evaluation of flicker. It is a figure for demonstrating the experiment of the relationship between the ratio of the emitted light intensity of 2 times of a display patch, and the subjective evaluation of flicker. It is a figure which shows the relationship between the display light beam value of 1st Embodiment, and the ratio of emitted light intensity. It is a figure which shows the light emission state by 2nd Embodiment. It is the figure which compared the appearance of the image | video of 3rd Embodiment, and the appearance of another image | video. It is a figure which shows the light emission state by 3rd Embodiment. It is a figure which shows schematic structure of the projection apparatus of 5th Embodiment. It is a figure which shows the light emission state by 5th Embodiment. It is a figure which shows the light emission state by 6th Embodiment. It is a figure which shows schematic structure of the projection apparatus of 7th Embodiment. It is a figure which shows the light emission state by 7th Embodiment. It is a figure which shows the light emission state by 8th Embodiment. It is a figure which shows the light emission state by 9th Embodiment. It is a figure which shows schematic structure of the projection apparatus of 10th Embodiment. It is a figure which shows the light emission state by 10th Embodiment. It is a figure which shows the light emission state by 11th Embodiment. It is a figure which shows the light emission state by 12th Embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of the projection apparatus according to the first embodiment. The projection apparatus 10 of the present embodiment is a liquid crystal projector that uses LEDs as light sources.
Reference numeral 11 denotes a white LED as a light source. Reference numeral 12 denotes a condensing correction optical system. Reference numeral 13 denotes a liquid crystal panel as a spatial modulation element. The liquid crystal panel 13 corresponds to an example of a display unit. Reference numeral 14 denotes a projection lens.
The light emitted from the LED 11 and diffused forward is condensed by the condensing correction optical system 12 and converted into parallel light. The parallel light is incident on the liquid crystal panel 13 and the light modulated by the image displayed on the liquid crystal panel 13 is output. The modulated light is magnified by the projection lens 14 and projected onto a screen (not shown).

FIG. 2 is a diagram showing an internal configuration of a projection apparatus using LEDs and a liquid crystal panel.
An image quality adjustment circuit 21 adjusts the image quality of the input video in accordance with the display device and viewer settings. Reference numeral 22 denotes an APL calculation circuit for calculating an APL value. The APL calculation circuit 22 corresponds to an example of a detection unit that detects flicker information indicating the likelihood of occurrence of flicker. A timing controller 23 controls the timing of the liquid crystal panel 27 and the LED 26. The timing controller 23 corresponds to an example of a control unit.
Reference numeral 24 denotes a DA converter. Reference numeral 25 denotes a driver for driving the LED 26. Reference numeral 26 denotes an LED as a light source. Reference numeral 27 denotes a liquid crystal panel as a spatial modulation element. 28 is a gate driver for driving the liquid crystal panel. Reference numeral 29 denotes a source driver for driving the liquid crystal panel.

Next, a schematic operation of the projection apparatus 10 will be described.
The image quality adjustment circuit 21 adjusts the image quality of the video signal (YpbPr signal) as the image information input to the projection device 10 using the characteristics of the liquid crystal panel 27 and the preference of the viewer as parameters to obtain an optimal image as RGB. Output as a signal. The RGB signals are output to the APL calculation circuit 22 and the timing controller 23. The APL calculation circuit 22 calculates an APL value. This process corresponds to an example of the process performed by the APL value calculation unit. Here, the APL value is an average picture level (Average Picture Level), and is an average value of the number of gradations of all pixels of an image to be displayed. The APL calculation circuit 22 obtains the screen light flux value from the APL value and the maximum light flux value determined by various settings. Details of this will be described later.

  The timing controller 23 transmits to the source driver 29 of the liquid crystal panel 27 the gradation data converted from the RGB signal into a digital value indicating the voltage. The timing controller 23 also transmits a timing signal for scanning at 60 Hz to the gate driver 28. The gate driver 28 and the source driver 29 drive the source electrode and the gate electrode of the liquid crystal panel 27, and the common electrode (not shown) is also driven to display an image on the liquid crystal panel 27.

Next, the operation of the LED 26 will be described.
The timing controller 23 outputs a voltage value corresponding to the current setting value to be passed through the LED 26 to the DA converter 24 for setting the current value. For example, if 20 mA is supplied as the current value when the LED 26 emits light, the voltage value corresponding to the current set value is 2 V, and if 4 mA is supplied as the current value during light emission, the voltage value corresponding to the current set value is 0. 4V.

FIG. 3 is a diagram illustrating a light emission state of the LED according to the first embodiment. In FIG. 3, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 3 shows the first luminous flux 31 when the image is dark, the first luminous flux 32 when the image is bright, and the second luminous flux 33 when the image is bright.
The light flux generated by the light emission of the LED 11 is slightly reduced by the condensing correction optical system 12, is reduced by the average image level (APL value) displayed on the liquid crystal panel 13, and is also slightly reduced and output by the projection lens 14.
When the APL value of the original image is small (when the image is dark), the screen light flux value is small. Therefore, flicker does not occur even if the light flux 31 is emitted only once in one frame with a frame frequency of 60 Hz.
When the APL value of the original image is large (when the image is bright), the screen light flux value is large, so flicker may occur if light is emitted for a short time within one frame with a frame frequency of 60 Hz. Therefore, it is necessary to reduce the occurrence of flicker by emitting light twice like the light beams 32 and 33.

Here, in order to reduce the occurrence of flicker, it is determined from the result of the subjective evaluation how much brightness is required to be emitted twice from the display.
FIG. 4 is a diagram illustrating a result of an experiment on the relationship between the luminance of the display patch and the subjective evaluation of flicker. FIG. 4A shows the relationship between the light emission time and the light emission intensity of the display patch. FIG. 4B shows a dark patch 41 and a bright patch 42. FIG. 4C is a graph 43 showing the subjective evaluation result.

Subjective evaluation was made into five-level evaluation values, and the evaluation criteria were set as follows.
4. Flicker subjective evaluation value in FIG. 4 5: Feel no flicker at all 4: Know that there is a slight flicker 3: Feel the flicker that can be tolerated 2: Feel the flicker that cannot be tolerated 1: The flicker is too strong Can't see

In this experiment, the emission intensity and the patch area were set so that the flicker occurred sufficiently. The light emission time was set to 1 ms at a frame frequency of 60 Hz, and the patch area was set to 300 cm ² .
Under this display condition, the brightness of the display patch was changed by changing the gradation of the display patch. Here, the gradation is changed so that the dark patch 41 changes to the bright patch 42, specifically, 0 Cd / m ^{2 to} 200 Cd / m ² . The result of experimenting the subjective evaluation is a graph 43.
From this result, it was found that the impulse evaluation light emission with a small duty ratio at a frame frequency of 60 Hz has a subjective evaluation value of 4 or more as long as it is 70 Cd / m ² or less, and can tolerate flicker.

In the projection apparatus 10, the relationship between the luminous flux value in the projection apparatus 10 and the luminance on the screen is determined as follows based on the area of the screen and the reflectance.
Luminance = Luminous flux / (Area x π) x Reflectance
Luminous flux = luminance × area × π / reflectance From this relationship, if the average screen value is 100 inches diagonal and the reflectance is 80%, the luminous flux = luminance × 11.8.
Also, as an installation situation that looks brighter, if the reflectance is 90% on a screen with a diagonal of 80 inches, the luminous flux = luminance × 6.7.
Therefore, as described above, when the luminance is 70 Cd / m ² or less, an average of about 800 Lumen or less is an allowable range of flicker. In addition, since the installation conditions vary, when the bright conditions are used, the allowable range of flicker is 470 Lumen≈about 500 Lumen or less.

Next, when the luminous flux is larger than 500 Lmenn, another subjective evaluation is carried out to determine the ratio of luminous intensity (luminous flux) that needs to be emitted when emitting twice in order to reduce the occurrence of flicker. Determine from the experiment.
FIG. 5 is a diagram showing the results of experiments on the relationship between the ratio of the emission intensity of the display patch twice and the subjective evaluation of flicker. FIG. 5A shows the relationship between the first light emission time and the light emission intensity 51, and the relationship between the second light emission time and the light emission intensity 52. FIG. 5B shows the display patch 53. FIG. 5C is a graph 54 showing the subjective evaluation results.
The ratio between the first emission intensity 51 and the second emission intensity 52 was changed such that the total integrated luminance of the display patches according to the first and second emission intensity was constant at 200 Cd / m ² . The display patch had an area of 300 mm ² and displayed all white.

From the subjective evaluation results, it was found that when the ratio of the first emission intensity to the second emission intensity is 1.0: 0.4 or more, the subjective evaluation value is 4 or more and flicker is acceptable.
Here, to facilitate later calculations, the emission intensity ratio of 1.0: 0.4 is normalized and replaced with 0.7: 0.3. Since this value is a value when the integrated luminance is 200 Cd / m ² , when bright conditions are used as described above, if 1340 Lumen≈about 1300 Lumen, 0.7: 0.3 is assumed. I found it good.

From the result of the subjective evaluation experiment as described above, for example, the ratio of the light emission intensity twice is set as follows. Here, the total display luminous flux value by two times of light emission is set to D (Lumen).
(Case 1) D ≦ 500Lumen
First emission intensity: 1.0
Second emission intensity: 0.0

(Case 2) 500Lumen <D <1300Lumen
First emission intensity: 1.0-0.3 × (D-500) / 900
Second emission intensity: 0.3 × (D−500) / 900

(Case 3) D ≧ 1300Lumen
First emission intensity: 0.7
Second emission intensity: 0.3

Here, the maximum light emission intensity of the LED is determined by the set value and mode of the projection apparatus 10, and the maximum luminous flux value is determined by narrowing the stop.
For example, in the projector 10 having the maximum luminous flux value of 2000 Lumen, in the PC mode, the brightness can be set, for example, between 1000 and 2000 Lumen. In the movie mode, for example, a setting between 300 and 1000 Lumen can be made. In order to increase the dark portion contrast, the aperture may be controlled by the APL value to dynamically darken the image. In this case, if the maximum luminous flux value is 1000 Lumen, the minimum luminous flux value changes between 125 Lumen and 1000 Lumen if the brightness is reduced to, for example, 1/8 brightness. The APL calculation circuit 22 obtains the display light flux value by multiplying the APL value by the maximum light flux value. This process corresponds to an example of a process performed by the display light beam value calculation unit. The display light flux value is an example of flicker information and serves as an index indicating the likelihood of flicker.
Thus, even if the display light flux value is a fixed value or a dynamic change value, the first emission intensity and the second emission intensity are controlled according to the display light flux value at that time.

Here, the screen light flux value is an instantaneous light flux value, and the integrated normal light flux value is as follows.
Luminous flux value = screen luminous flux value / duty Duty is a ratio of light emission time.
The display light flux value is a light flux value that varies depending on the image content, and is as follows.
Display beam value = Screen beam value x APL
The emission intensity is a value indicating a ratio, and is a ratio with respect to the maximum emission intensity.
FIG. 6 is a diagram showing the relationship between the display light flux value and the ratio of the light emission intensity in the first embodiment.
In FIG. 6, the horizontal axis represents the display light flux value, and the vertical axis represents the ratio of the second emission intensity when the first emission intensity is 1.0. FIG. 6 shows a control line 61 for determining the ratio between the first emission intensity and the second emission intensity from the display light flux value. In the control line 61, the ratio of the above-mentioned (case 1) and (case 3) is linearly connected when the display light flux value is between 500 and 1300 lumens. However, it is not limited to be linear, and may be curved.

  The timing controller 23 collates the display light flux value calculated by the APL calculation circuit 22 with the control expression (case 1) to (case 3) or the control line 61 of FIG. Get the intensity ratio. The timing controller 23 controls the LED 26 using the acquired control value. Specifically, the timing controller 23 causes the LED 26 to emit light only once when the display light flux value is small, and causes the LED 26 to emit light twice when the display light flux value is large. Further, when the display light flux value is large, the timing controller 23 changes the ratio of the first light emission intensity and the second light emission intensity according to the display light flux value. By performing such processing for each frame, flicker and motion blur of the displayed moving image are reduced. Note that the control equations (case 1) to (case 3) described above or the control line 61 shown in FIG. 6 are stored in the timing controller 23 in advance.

  As described above, according to the present embodiment, the occurrence of flicker and the occurrence of motion blur are reduced by controlling the number of times the LED emits light within the time during which one frame image is displayed in accordance with the probability of occurrence of flicker. be able to. In addition, when the LED emits light twice, the ratio of the first emission intensity and the second emission intensity is controlled according to the probability of occurrence of flicker, so that the occurrence of flicker can be reliably reduced.

(Second Embodiment)
Next, as a second embodiment, a relationship between an image and LED light emission when an intermediate image is generated from an original image having a frame frequency of 60 Hz and displayed at a frame frequency of 120 Hz will be described. In the present embodiment, the projection device 10 of the first embodiment is used.
FIG. 7 is a diagram showing a light emission state of the LED in the second embodiment.
In FIG. 7, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 7 shows a light beam 71 in the original image when the image is dark, a light beam 72 in the original image when the image is bright, and a light beam 73 in the intermediate image when the image is bright.

When the original image is dark, the screen light flux value is small as in the first embodiment, so flicker does not occur even if the light flux 71 is emitted only once in one frame with a frame frequency of 60 Hz.
On the other hand, when the original image is bright, the screen light flux value is large, so flicker may occur if short light emission is performed within one frame with a frame frequency of 60 Hz. Therefore, it is necessary to reduce the occurrence of flicker by emitting light twice with the light flux 72 of the original image and the light flux 73 of the intermediate image. Note that the intermediate image may be generated by the timing controller 23 or an image generation circuit (not shown).

  In the second embodiment, since an intermediate image is used, it is possible to display an image with less motion blur than in the first embodiment. In addition, even if an intermediate image generation error occurs, there is no second light emission or it is suppressed to about 40% of the first light emission, so that the viewer feels that the image is disturbed due to the intermediate image generation error. It becomes difficult.

(Third embodiment)
Next, how the image is viewed in the third embodiment will be described with reference to FIG. In the present embodiment, the projection device 10 of the first embodiment is used. FIG. 8 is a diagram comparing the appearance of an image according to the present embodiment with the appearance of another image.
FIG. 8A is a diagram showing how the display with a frame frequency of 60 Hz that emits impulse light is visible.
FIG. 8B is a diagram showing how a display with a frame frequency of 60 Hz inserted into hold light emission is black.
FIG. 8C is a diagram showing how the two-time lighting display looks bright and dark with hold light emission.
FIG. 8D is a diagram illustrating how the twice-lit display by the impulse light emission is seen.
FIG. 8E is a diagram showing how the twice-lit display according to the present embodiment is seen.
In each figure, the displayed object has a spherical shape and moves from right to left for each frame. In each figure, the vertical axis indicates time. In the case of an image with a frame frequency of 60 Hz, the image is switched every 16.67 ms. The movement of the line of sight is indicated by an arrow. An image synthesized along the movement of the line of sight (image seen by the viewer) is shown at the bottom.

In FIG. 8A, reference numeral 81 denotes a shape in which an image of a sphere is seen within one frame by impulse light emission. Reference numeral 82 denotes a shape in which an image of a sphere can be seen by combining several frames by impulse light emission.
In FIG. 8B, reference numeral 83 denotes a shape in which an image of a sphere can be seen within one frame by hold light emission. Reference numeral 84 denotes a shape in which an image of a sphere is seen by combining several frames by hold light emission.
In FIG. 8C, reference numeral 85 denotes a shape in which a sphere image can be seen in one frame by bright hold light emission. Reference numeral 86 denotes a shape in which an image of a sphere can be seen in one frame due to dark hold light emission. Reference numeral 87 denotes a shape in which an image of a sphere is seen by combining several frames by hold light emission.
In FIG. 8D, reference numeral 88 denotes a shape in which an image of a sphere is seen within one frame by the first light emission of impulse light emission. Reference numeral 89 denotes a shape in which an image of a sphere can be seen within one frame by the second light emission of the impulse light emission. Reference numeral 90 denotes a shape in which an image of a sphere is seen by combining several frames by impulse light emission.
In FIG. 8E, reference numeral 91 denotes a shape in which an image of a sphere is seen within one frame due to bright emission of impulse emission. Reference numeral 92 denotes a shape in which an image of a sphere can be seen within one frame due to the dark emission of hold emission. Reference numeral 93 denotes a shape in which an image of a sphere is seen by combining several frames by light emission according to the present embodiment.

  In FIG. 8A, only the first light emission time is displayed for each frame by impulse light emission. The appearance of each image is close to a sphere as shown by a shape 81, and the image seen by combining several frames is close to a sphere like a shape 82. Therefore, the appearance of the movement of the object is the best. However, when impulse light emission is performed at a frame frequency of 60 Hz, flickering is seriously generated, so that bright display cannot be performed.

  In FIG. 8B, only the first light emission time is displayed for each frame by hold light emission. The light emission time becomes longer as indicated by a shape 83 (hold-type light emission display). When this is added several frames in the direction of movement of the line of sight, as shown by a shape 84, it appears to be deformed into an ellipse. Since black is inserted and the hold time is halved, the degree is slightly improved, but it is deformed. If the time for black insertion is further increased, deformation is not caused, but conversely, it approaches impulse light emission, so that it becomes the same as in FIG. 8A, and flicker is severely generated.

In order to prevent the occurrence of flicker, light emission is performed twice within one frame as follows.
In FIG. 8C, there are a shape 85 that is visible by bright hold light emission for the first light emission time, and a shape 86 that is visible by dark hold light emission for the second light emission period. The shape 87 that appears by combining them according to the movement of the line of sight looks like a bright ellipse and a dark ellipse like a tail.
FIG. 8D shows impulse light emission so that it looks spherical.
In FIG. 8D, the shape 88 that can be seen by the first impulse emission appears close to a sphere. The shape 89 that can be seen by the second impulse light emission also appears to be close to a sphere, but is displayed with a delay in time, and thus deviates from the movement of the line of sight. The shape 90 that appears by combining them in accordance with the movement of the line of sight is called a so-called double blur, in which a sphere is doubled, and has a poor image quality.
FIG. 8E shows how the present embodiment looks.
In FIG. 8 (e), the shape 91 that can be seen by the first bright impulse emission appears close to a sphere. The shape 92 that can be seen by the second dark hold emission is a dark ellipse. A shape 93 that appears to be synthesized in accordance with the movement of the line of sight is a dark spherical image connected to a bright spherical image. In other words, the same shape as the moving shape appears bright, and a dark image such as a tail appears behind. The appearance of the shape 93 is not that the shape is deformed like the shape 84 or the shape 87, nor is it that the shape 93 is seen double. Although the shape 93 has a dark tail, it is natural as a way of seeing the movement of the object, and it is easy to be accepted by the viewer.

FIG. 9 is a diagram illustrating a light emission state of the LED according to the third embodiment.
In FIG. 9, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 9 shows a bright and short light beam 95 in the original image of the first frame, a dark and long light beam 96 in the original image of the first frame, a bright and short light beam 97 in the original image of the second frame, and a dark and long light beam in the original image of the second frame. A light beam 98 is shown.

  As shown in FIG. 9, the display as shown in FIG. 8E can be obtained by making the light emission of the LED 11 bright and short light emission and dark and long light emission within one frame. This display is more natural than the one shown in the first embodiment as a way of seeing the movement of the object, and is a way of being easily accepted by the viewer.

(Fourth embodiment)
Next, what has both 2nd Embodiment and 3rd Embodiment as 4th Embodiment is demonstrated. In the present embodiment, the projection device 10 of the first embodiment is used.
In the fourth embodiment, the original image and the intermediate image are alternately displayed as in the second embodiment, and the LED 11 repeatedly displays a bright short light beam and a dark long light beam as in the third embodiment. To do. That is, a bright and short light beam is displayed when the original image is displayed, and a dark and long light beam is displayed when the intermediate image is displayed.
By displaying in this way, the original image looks clear and the intermediate image becomes blurry, so that the disturbance of the image due to an intermediate image generation error becomes inconspicuous. Further, since the light emission is 120 Hz in total, flicker does not occur.

  In the projectors 10 of the first to fourth embodiments, the case where the white LED 11 is used as the light source has been described. However, the present invention is not limited to this case. For example, RGB three-color LEDs may be used as a light source, and three spatial modulation elements such as an LCD may be used for each color. The light source control described in the first to fourth embodiments may be performed. Doing so has a similar effect.

(Fifth embodiment)
Next, a projection apparatus using a lamp as a light source will be described in the fifth embodiment. When using a lamp as a light source, it is difficult to control the amount of light quickly compared to using an LED as a light source. Below, the structure and control method of the projection apparatus which used the lamp for the light source are demonstrated.

FIG. 10A is a diagram illustrating a schematic configuration of a projection apparatus according to the fifth embodiment. FIG. 10B is a front view showing the configuration of the rotating wheel 102. The projection apparatus 100 of the present embodiment is a liquid crystal projector that uses a lamp as a light source and a rotating wheel.
Reference numeral 101 denotes a lamp as a light source. Reference numeral 12 denotes a condensing correction optical system. Reference numeral 13 denotes a liquid crystal panel as a spatial modulation element. Reference numeral 102 denotes a rotating wheel that is rotated by a rotary motor or the like. Reference numeral 14 denotes a projection lens.
As shown in FIG. 10 (b), the rotating wheel 102 has a transparent portion (first transmission portion) 102a with a narrow slit interval and a half gray portion (second transmission portion) 102b with a wide slit interval in the circumferential direction. Are formed at predetermined intervals. The transparent portion 102a has a higher light transmittance than the half gray portion 102b. The rotating wheel 102 is configured in two cycles in which the transparent portion 102a and the half gray portion 102b pass between the liquid crystal panel 13 and the projection lens 14 twice in one rotation. In addition, it is not restricted to 2 periods, The rotation speed of the rotating wheel 102 can be restrained low by setting it as 3 periods or more. The timing controller 23 rotates the rotating wheel 102 in accordance with the display timing via a rotary motor.

  The light emitted from the lamp 101 and diffused forward is condensed by the condensing correction optical system 12 and converted into parallel light. The parallel light is incident on the liquid crystal panel 13 and the light modulated by the image displayed on the liquid crystal panel 13 is output. Of the modulated light, only the light that has passed through the transparent portion 102 a or the half gray portion 102 b of the rotating wheel 102 is emitted to the projection lens 14. Then, the light enlarged by the projection lens 14 is projected onto a screen (not shown). The internal configuration of the projection apparatus 100 can be configured by replacing the LED of the projection apparatus shown in FIG.

FIG. 11 is a diagram illustrating a light emission state of the projection apparatus 100 according to the fifth embodiment.
In FIG. 11, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 11 shows a bright and short light beam 111 in the original image of the first frame, a dark and long light beam 112 in the original image of the first frame, a bright and short light beam 113 in the original image of the second frame, and a dark and long light beam in the original image of the second frame. A light beam 114 is shown. The light beams 111 and 113 are transmitted through the transparent portion 102a, and the light beams 112 and 114 are transmitted through the half gray portion 102b.

The lamp 101 is difficult to control the amount of light in a short time like the LED 11. Therefore, in the projection apparatus 100 of the present embodiment, the rotating wheel 102 is rotated to realize a short and bright light emitting state and a long and dark light emitting state. Therefore, also in this embodiment, a display as shown in FIG.
Further, since the lamp 101 has a larger light amount than the LED 11, even if the amount by which the light amount is reduced by the rotating wheel 102 is subtracted, a brighter projection than the projection device using the LED 11 is possible.

(Sixth embodiment)
Next, display using an intermediate image in the sixth embodiment will be described. In the present embodiment, the projection device 100 of the fifth embodiment is used.
FIG. 12 is a diagram illustrating a light emission state of the projection apparatus 100 according to the sixth embodiment.
In FIG. 12, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 12 shows a bright and short light beam 121 in the original image of the first frame, a dark and long light beam 122 in the intermediate image of the first frame, a bright and short light beam 123 in the original image of the second frame, and a dark and long light in the intermediate image of the second frame. A light beam 124 is shown. The light beams 121 and 123 are transmitted through the transparent portion 102a, and the light beams 122 and 124 are transmitted through the half gray portion 102b.
Since an intermediate image is used in the sixth embodiment, it is possible to display an image with less moving image blur as compared with the fifth embodiment.
Thus, even the projection apparatus 100 using the lamp 101 as the light source can realize a short and bright light emission state and a long and dark light emission state, and the tail can be seen by the long and dark light emission, so that the movement of the object can be seen Can make viewers feel natural.

(Seventh embodiment)
Next, in a seventh embodiment, a hybrid light source projector 130 using two lamps and LEDs as a light source will be described.
FIG. 13 is a diagram showing a schematic configuration of a projection apparatus according to the seventh embodiment. The projection device 130 of this embodiment is a liquid crystal projector that uses a lamp (first light source) and an LED (second light source) as light sources.
Reference numeral 131 denotes a white LED as a light source. Reference numeral 132 denotes a lamp as a light source. Reference numeral 133 denotes a prism that combines light from two directions. Reference numeral 12 denotes a condensing correction optical system. Reference numeral 13 denotes a liquid crystal panel as a spatial modulation element. Reference numeral 14 denotes a projection lens. In the projection device 130, a light beam having a desired condition can be obtained by combining the light from both the LED 131 and the lamp 132. A specific light beam will be described below. Note that the internal configuration of the projection device 130 can be configured by adding a lamp 132 or the like in parallel with the LEDs of the projection device shown in FIG.

FIG. 14 is a diagram showing a light emission state in the seventh embodiment.
In FIG. 14, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 14 shows the bright and short luminous flux 141 of the LED for the original image of the first frame, the dark and continuous light emission 142 by the lamp, and the bright and short luminous flux 143 of the LED for the original image of the second frame. The timing for emitting the LED 131 needs to be performed in the first half of one frame.

The timing controller 23 always causes the lamp 132 to emit light so that it is about 1/3 to about 4/5 of the total light emission amount, and causes the LED 131 to be about 1/5 to about 1/3 of the total light emission amount. Makes it light up momentarily. By making it emit light in this way, the viewer sees both light emissions added together. In the moving display part, following the good display by the LED 131, the tail by the lamp 132 is added together. It is possible to make the viewer feel that such an appearance is natural as an appearance of the movement of the object.
This is because the timing at which the LED 131 emits light is set to the first half in one frame. If the timing at which the LED 131 emits light is set to the latter half of one frame, the tailing component by the lamp 132 appears on the front side of the movement and looks unnatural.

Further, flicker is generated only by the short light emission of the LED 131, but the flicker can be reduced by continuous light emission by the lamp 132.
Here, based on the subjective evaluation result of FIG. 5, the ratio of the luminous flux of the LED 131 and the luminous flux of the lamp 132 per frame is basically 0.33: 0.67. However, the timing controller 23 sets LED: lamp = 0.67: 0.33 when importance is attached to motion characteristics, and LED: lamp = 0.2: 0.8 indicates importance when flicker suppression is emphasized. Can be changed.

(Eighth embodiment)
Next, display using an intermediate image in the eighth embodiment will be described. In the present embodiment, the projection device 130 of the seventh embodiment is used.
FIG. 15 is a diagram illustrating a light emission state of the projection device 130 according to the eighth embodiment.
In FIG. 15, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 15 shows the bright and short luminous flux 151 of the LED in the original image of the first frame, the dark and continuous light emission 152 by the lamp, and the bright and short luminous flux 153 of the LED in the original image of the second frame and the intermediate image of the second frame. A dark short luminous flux 154 of the LED is shown. Here, dark and short light emission is performed once for each intermediate image of the second frame.

As shown in FIG. 15, the LED 131 emits light in the original image and does not emit light in the intermediate image, or causes the LED 131 to emit light darkly.
Since an intermediate image is used in the eighth embodiment, tailing can be made smaller than in the seventh embodiment. Further, as in the second and sixth embodiments, image disturbance due to an intermediate image generation error becomes inconspicuous. Further, by causing the LED 131 to emit light darkly like a light beam 154 shown in FIG. 15, it is possible to further reduce the occurrence of flicker as compared with the seventh embodiment.

(Ninth embodiment)
Next, in the ninth embodiment, a case where the flicker is reduced by pulsating the luminous flux of the lamp light source will be described. In the present embodiment, the projection device 130 of the seventh embodiment is used.
FIG. 16 is a diagram illustrating a light emission state of the projection device 130 according to the ninth embodiment.
In FIG. 16, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 16 shows the bright and short luminous flux 161 of the LED in the original image of the first frame, the pulsating light emission 162 by the lamp, and the bright and short luminous flux 163 of the LED in the original image of the second frame.

As shown in FIG. 16, the LED 131 emits light in the original image and does not emit light in the intermediate image. In addition, as shown in FIG. 16, the lamp 132 emits light in a pulsating manner so that it is slightly dark in the original image and slightly bright in the intermediate image.
This pulsation ratio will be specifically described.
For example, in the case of LED: lamp = 0.33: 0.67, when the average luminous flux of the lamp is 0.67 and the dark luminous flux of the lamp: bright luminous flux = 0.4: 0.6, the dark luminous flux of the lamp : Bright light flux = 0.27: 0.4, so the following formula is obtained.
Light flux by LED + dark lamp = 0.33 + 0.27 = 0.6
Luminous flux from bright lamp = 0.4
According to the calculation result, the ratio of the luminous flux in the original image and the intermediate image is 0.6: 0.4, that is, 1.0: 0.67, so flicker does not occur when referring to the subjective evaluation result of FIG.

  For example, in the case of LED: lamp = 0.5: 0.5, the calculation is performed in the same manner as described above, the ratio of the luminous flux in the original image and the intermediate image is 0.7: 0.3, that is, 1.0: 0. Therefore, flicker does not occur when referring to the subjective evaluation result of FIG.

In the ninth embodiment, flickering due to light emission of the LED can be reduced by emitting light by pulsating the lamp.
In the seventh to ninth embodiments described above, it is possible to increase the total amount of light by combining the lamp 132 and the LED 131 into a light source. In addition, when the lamp 132 is burned out, the projection using only the LED 131 is urgently possible.

(Tenth embodiment)
Next, in a tenth embodiment, a projection device 170 that dynamically controls opening and closing of a diaphragm will be described.
FIG. 17 is a diagram illustrating a schematic configuration of a projection apparatus according to the tenth embodiment. The projection apparatus 170 of this embodiment is a liquid crystal projector using a lamp and a diaphragm mechanism.
Reference numeral 101 denotes a lamp as a light source. Reference numeral 12 denotes a condensing correction optical system. Reference numeral 13 denotes a liquid crystal panel as a spatial modulation element. Reference numeral 171 denotes a light guide lens. Reference numeral 172 denotes an aperture mechanism. Reference numeral 14 denotes a projection lens. The aperture mechanism 172 may be an aperture that is opened and closed by a mechanical rotation mechanism, an electromagnetic aperture, or an optical aperture using liquid crystal or the like. The timing controller 23 opens and closes the aperture mechanism 172 in accordance with the display timing. The internal configuration of the projection apparatus 170 can be configured by replacing the LED of the projection apparatus shown in FIG.

FIG. 18 is a diagram illustrating a light emission state of the projection device 170 according to the tenth embodiment.
In FIG. 18, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 18 shows a bright and short light beam 181 in the original image of the first frame, a dark and long light beam 182 in the original image of the first frame, a bright and short light beam 183 in the original image of the second frame, and a dark and long light beam in the original image of the second frame. A light beam 184 is shown. Here, the aperture mechanism 172 is fully opened by the light beams 181 and 183, the aperture mechanism 172 is fully opened by the light beams 182 and 184, and the aperture mechanism 172 is fully closed otherwise.

The lamp 101 is difficult to control the amount of light in a short time like the LED 11. Therefore, in the projection device 170 of the present embodiment, the diaphragm mechanism 172 is used to realize a short and bright light emission state and a long and dark light emission state. That is, the timing controller 23 controls the number of times of light emission and the light emission time of the lamp 101 by controlling the opening and closing of the aperture mechanism 172 within the time during which one frame image is displayed according to the probability of occurrence of flicker. Therefore, a display as shown in FIG.
Further, since the lamp 101 has a larger light amount than the LED 11, even if the amount by which the light amount is reduced by the diaphragm mechanism 172 is subtracted, a brighter projection than the projection device using the LED 11 is possible.

(Eleventh embodiment)
Next, display using an intermediate image in the eleventh embodiment will be described. In the present embodiment, the projection device 170 of the tenth embodiment is used.
FIG. 19 is a diagram illustrating a light emission state of the projection device 170 according to the eleventh embodiment.
In FIG. 19, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 19 shows a bright and short light beam 191 in the original image of the first frame, a dark and long light beam 192 in the intermediate image of the first frame, a bright and short light beam 193 in the original image of the second frame, and a dark and long light beam in the intermediate image of the second frame. A light beam 194 is shown. Here, the diaphragm mechanism 172 is fully opened by the light beams 191 and 193, the diaphragm mechanism 172 is fully opened by the light beams 192 and 194, and the diaphragm mechanism 172 is fully closed otherwise.
Since the intermediate image is used in the eleventh embodiment, it is possible to display an image with less moving image blur as compared with the tenth embodiment.

(Twelfth embodiment)
Next, the light emission state in the twelfth embodiment will be described. In the present embodiment, the projection device 170 of the tenth embodiment is used.
FIG. 20 is a diagram illustrating a light emission state of the projection device 170 according to the twelfth embodiment.
In FIG. 20, the horizontal axis indicates the passage of time, and the vertical axis indicates the screen light flux value. FIG. 20 shows a bright and short light beam 201 in the original image of the first frame, a light beam 202 by light emission at a certain level, and a bright and short light beam 203 in the original image of the second frame. Here, the diaphragm mechanism 172 is fully opened with the light beam 201, and the diaphragm mechanism 172 is opened by one fifth with the light beam 202.

The timing controller 23 opens the diaphragm mechanism 172 for about one-fifth over the entire display time, and fully opens the diaphragm mechanism 172 for a short time in the first half of one frame.
In the twelfth embodiment, the lamp 101 and the diaphragm mechanism 172 are used to realize a short and bright light emission state and a very long and dark light emission state. Therefore, it is possible to obtain a light emission state similar to that of the seventh embodiment without using the LED 11, and the same effect can be obtained.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
The present invention can also be realized by executing the following processing. In other words, this is a process in which a program that realizes the functions of the above-described embodiments is supplied to the projection apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the projection apparatus reads and executes the program.

  The present invention can be used for a projection apparatus that projects a hold-type display device with a light source, such as a rear projector, a front projector, and a movie projector.

  DESCRIPTION OF SYMBOLS 10: Projection apparatus 11: LED 12: Condensing correction | amendment optical system 13: Liquid crystal panel 14: Projection lens 21: Image quality adjustment circuit 22: APL calculation circuit 23: Timing controller 24: DA converter 25: Driver 26: LED 101: Projection apparatus 101: Lamp 102: Rotating wheel 130: Projector 131: LED 132: Lamp 133: Prism 170: Projector 171: Lens 172: Aperture mechanism

Claims (11)

A projection device that displays an image by causing a light source to emit light,
Input means for inputting image data;
An image to be applied to the projection device from the plurality of image projection modes among the gradation value indicated by the image data input by the input means and the maximum luminous flux value set in advance different for each of the plurality of image projection modes. Evaluation means for determining flicker information indicating the perception of flicker based on the maximum luminous flux value corresponding to the image projection mode selected as the projection mode;
Flicker in which the number of times of light emission of the light source within a time corresponding to an image of one frame corresponding to the image data input by the input unit is determined by the evaluation unit based on the gradation value and the maximum luminous flux value And a control means for controlling to determine based on the information . When the flicker information indicating that the flicker is easily perceived is determined by the evaluation means, the control means sets the number of light emission times of the light source within the time corresponding to the image of the one frame, and 2. The projection apparatus according to claim 1, wherein a ratio between a light emission intensity of a first light emission and a light emission intensity of a second light emission of the light source is controlled according to the flicker information .   The projection apparatus according to claim 2, wherein the control unit reduces a light emission intensity in the second light emission compared to a light emission intensity in the first light emission of the light source.   4. The projection apparatus according to claim 2, wherein the control unit makes the light emission time in the second light emission longer than the light emission time in the first light emission of the light source. Generating means for generating intermediate image data from the image data input by the input means;
If flicker information for said image data determined by the evaluation means, flicker is indicates that likely to be perceived,
The control means causes the light source to emit light for the first time within a time period for displaying an image according to the image data, and causes the light source to emit light for the second time within a time period for displaying the intermediate image according to the intermediate image data. While
If the flicker information for the image data determined by the evaluation means does not indicate that flicker is easily perceived ,
The control means causes the light source to emit light within a time period for displaying an image according to the image data, and does not cause the light source to emit light within a time period for displaying an intermediate image according to the intermediate image data. The projection apparatus according to any one of claims 1 to 4. The evaluation means includes
APL value calculating means for calculating an APL value obtained by averaging the gradation values of the image based on the image data input by the input means;
Display light flux value calculating means for calculating a display light flux value based on the APL value calculated by the APL value calculating means and a maximum light flux value corresponding to an image projection mode selected from the plurality of image projection modes; Have
The projection apparatus according to claim 1, wherein the flicker information is a display light beam value calculated by the display light beam value calculation unit.   When the display light flux value calculated by the display light flux value calculation means is greater than 500 Lumen, the control means sets the number of times of light emission of the light source within the time corresponding to the one frame image, and the display light flux The number of times of light emission of the light source in a time corresponding to the image of the one frame is set to one when the display light flux value calculated by the value calculation means is 500 Lumen or less. Projection device.   The control means causes the light source to emit a first light emission and a second light emission time longer than the first light emission within a time period for displaying an image according to the image data input by the input means. 8. The projection apparatus according to claim 1, wherein light emission by the light source is controlled so that the first light emission is brighter than the second light emission.   9. The projection apparatus according to claim 1, wherein the plurality of image projection modes include at least a PC mode and a movie mode having a maximum light flux value lower than that of the PC mode. A method for controlling a projection device that displays an image by causing a light source to emit light,
An input step for inputting image data;
An image to be applied to the projection device from the plurality of image projection modes among the gradation value indicated by the image data input in the input step and the maximum luminous flux value set in advance different for each of the plurality of image projection modes. An evaluation step for determining flicker information indicating a flicker perceptibility based on a maximum luminous flux value corresponding to the image projection mode selected as the projection mode;
Flicker in which the number of times of light emission of the light source within a time corresponding to an image of one frame corresponding to the image data input in the input step is determined based on the gradation value and the maximum luminous flux value in the evaluation step And a control step for controlling to determine based on the information . A program for causing a computer to execute the control method according to claim 10.