Projection system and control method of projection system

Abstract

The projection system of the present disclosure includes: a light source that outputs light of multiple colors; a display panel that includes a light modulation element set for each pixel and modulates the light output from the light source; a projection optical system that projects the light that has passed through the display panel; and a controller that controls the light output of each color of the light source along the time axis direction. This configuration is adopted to achieve improvement in the brightness of the projected image / screen and prevention of color mixing in field sequential driving.

Description

Technical Field

[0001] The present disclosure relates to a projection system (projector / projection-type display device) and a control method of the projection system. Background Art

[0002] In the projection system, display methods for display panels include a plane partition method and a field sequential method (field color sequential method). The plane partition method is a method of performing full-color display by spatially displaying the three primary colors of R (red), G (green), and B (blue) and spatially mixing these colors. The field sequential method is a method of performing full-color display by temporally displaying images of R, G, and B sequentially and temporally mixing these images. Compared with the spatial plane partition method (plane partition method), the field sequential method can obtain a brighter image.

[0003] Incidentally, in the case of performing color sequential driving in a field sequential (time division) manner, the weak responsivity of the light modulation element may lead to a problem of a reduction in the amount of reflected light and color mixing of adjacent colors. PTL 1 (Japanese Unexamined Patent Application Publication No. 2006-58900) describes a technology for improving the brightness of a projected image / screen by performing light source control in a graded manner in performing color sequential display to correct the responsivity of a light valve light source.

[0004] Reference List

[0005] Patent Literature

[0006] PTL 1: Japanese Unexamined Patent Application Publication No. 2006-58900. Summary of the invention

[0007] Problems to be solved by the present invention

[0008] According to the related art described in the above PTL 1, it is possible to prevent display from being dimmed in performing color sequential display. However, in the related art, color mixing caused by the weak responsivity of the light modulation element is not considered.

[0009] An object of the present disclosure is to provide a projection system and a control method of the projection system that can improve the brightness of a projected image / screen and prevent color mixing.

[0010] Means of solving the problem

[0011] The projection system of the present disclosure for achieving the above-mentioned invention object comprises:

[0012] A light source that outputs light in multiple colors;

[0013] A display panel including a light modulation element provided for each pixel and modulating light output from the light source;

[0014] a projection optical system that projects the light that has passed through the display panel; and

[0015] A controller controls the light output of each color of the light source along a time axis direction.

[0016] The present disclosure provides a method for controlling a projection system to achieve the above-mentioned object of the invention, wherein the projection system comprises:

[0017] A light source that outputs light in multiple colors;

[0018] a display panel including a light modulation element provided for each pixel and modulating light output from the light source; and

[0019] a projection optical system that projects the light that has passed through the display panel,

[0020] The control method comprises:

[0021] When controlling the projection system, the light output of each color of the light source is controlled along the time axis direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [ Figure 1 ] Figure 1 is a system configuration diagram illustrating an example of a basic system configuration of a projection system.

[0023] [ Figure 2 ] Figure 2 It is a diagram describing the display principle of the field sequential method.

[0024] [ Figure 3 ] Figure 3 is a diagram describing a problem in the case where color sequential driving is performed in a field sequential (time division) manner in a single liquid crystal panel.

[0025] [ Figure 4 ] Figure 4 is a system configuration diagram illustrating a system configuration of a single panel type projection system according to Embodiment 1.

[0026] [Figure 5] Figure 5A is an explanatory diagram of light output control of a light source in a projection system according to Embodiment 1, Figure 5B is a diagram describing that black display is inserted into the color mixing area.

[0027] [ Figure 6 ] Figure 6 is a system configuration diagram illustrating a system configuration of a projection system according to Embodiment 2.

[0028] [ Figure 7 ] Figure 7 is a flowchart illustrating the flow of a process of changing a light source driving mode.

[0029] [ Figure 8 ] Figure 8 is a diagram illustrating the result of the process of changing the light source driving mode.

[0030] [ Fig. 9 ] Fig. 9 It is an explanatory diagram about the light source control interval according to Embodiment 3.

[0031] [ Fig.10 ] Fig.10 is a system configuration diagram illustrating a system configuration of a projection system according to Embodiment 4.

[0032] [ Fig.11 ] Fig.11 is a system configuration diagram illustrating a system configuration of a projection system according to Embodiment 5.

[0033] [ Fig.12 ] Fig.12 is a system configuration diagram illustrating a system configuration of a projection system according to Embodiment 6. DETAILED DESCRIPTION

[0034] Hereinafter, the mode for implementing the technology of the present disclosure (hereinafter referred to as "implementation mode") will be described in detail with reference to the accompanying drawings. The technology of the present disclosure is not limited to these implementation modes. In the following description, the same components or components with the same functions are represented by the same reference numerals, and repeated descriptions are omitted. It should be noted that the description is given in the following order.

[0035] 1. Overall description of the projection system and control method thereof of the present disclosure

[0036] 2. Overview of the projection system

[0037] 2-1. Basic system configuration example

[0038] 2-2. About the Field Sequential Method

[0039] 3. Projection system according to an embodiment

[0040] 3-1. Example 1 (System Configuration Example of Single-panel Type)

[0041] 3-1-1. System Configuration

[0042] 3-1-2. Operation and operation

[0043] 3-2. Example 2 (Improvement of Example 1: Example of performing light source control in consideration of panel temperature)

[0044] 3-2-1. System Configuration

[0045] 3-2-2. Processing of changing the light source driving mode

[0046] 3-3. Example 3 (Improvement of Example 1: Example with variable light source control interval)

[0047] 3-4. Example 4 (Double-panel system configuration example)

[0048] 3-5. Example 5 (Improvement of Example 4: Example of driving the light source in consideration of the temperatures of both panels)

[0049] 3-6. Example 6 (Improvement of Example 4: Example of driving the light source in consideration of the temperature of one of the two panels)

[0050] 4. Improvement example

[0051] 5. Possible Configurations of the Disclosure

[0052] <Overall Description of the Projection System and Control Method of the Present Disclosure>

[0053] In the projection system of the present disclosure, the display panel may be configured as a liquid crystal panel, which includes a liquid crystal element as a light modulation element. In addition, the controller may be configured to perform field sequential driving for color sequentially driving the light source in a time division manner.

[0054] In the projection system and control method of the present disclosure including the above-mentioned preferred configuration, the controller may have a configuration in which the light output of each color of the light source is controlled in a graded manner along the time axis direction according to the responsiveness of the liquid crystal panel, and preferably, has a configuration in which the light output between one color and another color of the light source is reduced or turned off.

[0055] In addition, the projection system and control method of the present disclosure including the above preferred configuration can adopt a configuration that controls the light output along the time axis so as to be proportional to the response waveform of the liquid crystal panel. In addition, a configuration that independently changes the light output for each color of the light source according to the responsiveness of the liquid crystal panel can be adopted.

[0056] In addition, in the projection system and control method thereof of the present disclosure including the above-mentioned preferred configuration, the controller may be configured to drive the light source in a light source driving mode, wherein the driving timing of the light source driving mode has a phase difference corresponding to the temperature of the liquid crystal panel relative to the driving timing of the liquid crystal panel. In addition, a configuration may be adopted in which a temperature sensor for detecting the temperature of the liquid crystal panel and a memory for storing the light source driving mode for the temperature of the driving timing of the light source relative to the driving timing of the liquid crystal panel as a light source driving table are included, and the controller may be configured to obtain the light source driving mode corresponding to the temperature detected by the temperature sensor from the light source driving table and drive the light source based on the light source driving mode obtained thereby.

[0057] In addition, in the projection system and control method of the present disclosure including the above-mentioned preferred configuration, the controller may have a configuration in which the light source control interval is controllable along the time axis direction, and preferably has a configuration in which the light source control interval is narrower in a region where the response waveform of the liquid crystal panel changes steeply than in another region.

[0058] In addition, in the projection system and control method thereof of the present disclosure including the above-mentioned preferred configuration, the display panel may have a dual panel configuration provided with two liquid crystal panels. In addition, a configuration may be adopted in which a temperature sensor for detecting the temperature of at least one of the two liquid crystal panels and a memory for storing a light source driving mode for the driving timing of the light source relative to the temperature of the driving timing of the two liquid crystal panels as a light source driving table are included, and the controller may be configured to obtain a light source driving mode corresponding to the temperature detected by the temperature sensor provided in at least one of the two liquid crystal panels from the light source driving table and drive the light source based on the light source driving mode thus obtained.

[0059] <Overview of projection system>

[0060] First, an overview of a projection system (projector / projection display device) to which the technology of the present disclosure is applied is described. Here, a projection system using a liquid crystal panel as a display panel is described as an example. The liquid crystal panel includes a liquid crystal element as a light modulation element provided for each pixel.

[0061] Liquid crystal panels are classified into transmissive and reflective types. Further, as silicon materials used in thin film transistors (TFT: Thin Film Transistor) used in pixels, amorphous silicon (amorphous semiconductor) and polycrystalline silicon (polycrystalline semiconductor) are generally used in transmissive liquid crystal panels. In reflective liquid crystal panels, single crystal silicon is generally used.

[0062] [Basic system configuration example]

[0063] Figure 1Here, a system configuration in which one reflective liquid crystal panel using LCOS (Liquid Crystal On Silicon) as a light modulation element, that is, a single panel is used is described.

[0064] like Figure 1 As shown in , the projection system 10 according to the present embodiment includes solid-state light sources 11R, 11G, and 11B of R (red), G (green), and B (blue). For example, any light source such as a laser diode (LD), a light emitting diode (LED), an organic light emitting diode (OLED), a YAG phosphor light source, and a lamp may be used as each of the solid-state light sources 11R, 11G, and 11B.

[0065] Light output from solid-state light sources 11R, 11G, 11B of R, G, B, respectively, passes through lenses 12R, 12G, 12B, and then passes through dichroic mirrors 13 and 14 and lens 15 to enter rod integrator 16. Light homogenized by rod integrator 16 passes through lens 17, reflector 18, total reflection prism 19, and is applied to display panel (liquid crystal panel) 20. Total reflection prism 19 includes a combination of two triangular prisms.

[0066] The liquid crystal panel 20 has a configuration in which pixels are arranged in a two-dimensional matrix (rows and columns) and a liquid crystal material is provided as a liquid modulation element for each pixel. The solid-state light sources 11R, 11G, 11B and the liquid crystal panel 20 are controlled by a display controller 22. The display controller 22 includes a receiver 221, a signal processor 222, a CPU (Central Processing Unit) 223, a light source control unit 224, and a liquid crystal panel controller 225.

[0067] In the display controller 22 having the above configuration, in the case of using the single-panel liquid crystal panel 20, the light source control unit 224 temporally controls the light emission of each of the light sources of each color (i.e., the solid-state light sources 11R, 11G, 11B of R, G, B) under the control of the CPU 223. The signal processor 222 performs predetermined signal processing on an image signal input from the outside through the receiver 221 under the control of the CPU 223, and supplies the image signal as image data to the liquid crystal panel controller 225.

[0068] The liquid crystal panel controller 225 drives the liquid crystal panel 20 based on the image data supplied from the signal processor 222. Then, the light modulated by the liquid crystal panel 20 according to the input image data is projected onto the screen 30 as a projected image through the total reflection prism 19 and the projection lens 21. The screen 30 is an example of a projection target.

[0069] [About Field Sequential Method]

[0070] In the projection system having the above configuration, the field sequential method is used as a display method of the liquid crystal panel 20. In the method of performing color sequential driving in a field sequential (time division) manner by the field sequential method, as shown in FIG. Figure 2 As shown in , full color display is performed by temporally sequentially displaying images of a plurality of colors (for example, R (red), G (green), and B (blue) as three primary colors) and temporally mixing the images.

[0071] Occasionally, in the case of performing color sequential driving in a field sequential (time division) manner in a single-panel liquid crystal panel, the weak responsiveness of the liquid crystal panel may cause problems such as a decrease in the amount of reflected light and color mixing of adjacent colors. Figure 3 In the embodiment, the intrinsic amount of reflected light is not obtained by the blunt rise of the liquid crystal response waveform (the portion surrounded by the dotted line A). In addition, the fall of the liquid crystal response waveform is located on the luminescence of the adjacent color (the portion surrounded by the dotted line B), which causes color mixing.

[0072] The problem of reduced amount of reflected light can be solved by applying a higher voltage than usual to the liquid crystal element when changing the color on the screen so that the liquid crystal element moves (conversion of the emission color) faster. However, in this case, the upper limit voltage that can be applied to the liquid crystal panel is determined, so this mechanism can only be applied to halftones. In addition, the drop of the liquid crystal response waveform is further blunted, which leads to an expansion of the color mixing area.

[0073] The problem of color mixing can be avoided by making the light source emit light in a section other than the section where color mixing occurs. However, in this case, the light emitting section of the light source is shortened, which reduces the brightness of the projected image.

[0074] <Projection System According to Embodiment>

[0075] In an embodiment of the present disclosure, in a projection system including a light source that outputs light of multiple colors and a single-panel or double-panel liquid crystal panel as a display panel, when the light source is driven in a time-division color sequence, the light output of each color of the light source is controlled along the time axis direction. As described above, in field sequential driving, the light output of each color of the light source is controlled along the time axis direction, which can improve the brightness of the projected image / screen and prevent color mixing. In addition, the light output of the light source can be effectively utilized, which can reduce the power consumption of the display device and suppress the temperature rise.

[0076] Hereinafter, a specific example of a projection system according to the present disclosure is described, which controls the light output of each color of a light source along a time axis direction in field sequential driving for color sequential driving in a time division manner.

[0077] [Example 1]

[0078] Embodiment 1 is a system configuration example of a single-panel type projection system according to an embodiment of the present disclosure. Figure 4 is a diagram illustrating a system configuration of a single-panel type projection system according to Embodiment 1.

[0079] (System Configuration)

[0080] In addition to an optical system including a rod integrator 16 and the like, a liquid crystal panel 20, and a projection optical system including a projection lens 21, the projection system 10 according to Example 1 also includes a light source (light source unit) 41, an image processing engine 42, a system controller 43, and a light source driving unit 44.

[0081] The light source 41 includes, for example, solid-state light sources 11R, 11G, 11B that respectively output (emit) light as a plurality of colors of R (red), G (green), and B (blue), and lenses 12R, 12G, 12B that are provided respectively corresponding to the solid-state light sources 11R, 11G, and 11B. For example, any light source such as a laser diode (LD), a light emitting diode (LED), an organic light emitting diode (OLED), a YAG phosphor light source, and a lamp can be used as each of the solid-state light sources 11R, 11G, and 11B.

[0082] The image processing engine 42 includes an image processor 421 and a synchronization signal detector 422. The image processor 421 performs various image processing such as gamma (γ) processing and processing of changing synchronization timing on an image signal (picture signal) input from the outside. The image signal processed by the image processor 421 is supplied to the liquid crystal panel 20. The synchronization signal detector 422 detects a synchronization signal contained in the image signal input from the outside.

[0083] The system controller 43 includes, for example, a microprocessor, and has a function of a light source control unit 431. A synchronization signal detected by the synchronization signal detector 422 is supplied from the image processing engine 42 to the light source control unit 431. The light source control unit 431 performs setting of a light emission timing corresponding to the synchronization signal detected by the synchronization signal detector 422 of the image processing engine 42, and controls light output of the light source driving unit 44 for driving each of the solid-state light sources 11R, 11G, 11B of the light source 41.

[0084] (Operation and Operation)

[0085] Reference Figure 5A The operation and performance of the light source control in the projection system 10 according to Embodiment 1 having the above-described configuration are described. Figure 5A 1 is an explanatory diagram of light output control of the light source 41 in the projection system 10 according to Embodiment 1.

[0086] The light source control unit 431, which is one of the functional sections included in the system controller 43, does not keep the light output of the light source 41 constant as shown in 5B, but controls the light output of each color of the light source 41 in a stepwise manner along the time axis direction according to the response waveform (reflectivity) representing the responsiveness of the liquid crystal panel 20. In addition, the light source control unit 431 reduces the difference between one color and another color of the light source 41, for example, between Figure 5B In the embodiment of the embodiment, the light output of the light source 41 in the color mixing area is reduced (i.e., the light amount is suppressed), or the light output is switched to the off state (i.e., the non-light emitting state). Here, switching the light output of the light source 41 in the color mixing area to the off state (non-light emitting state) means as follows: Figure 5B Inserting black into the color mixing area as shown in .

[0087] As described above, the light output of each color of the light source 41 is controlled in a graded manner along the time axis direction according to the responsiveness of the liquid crystal panel 20, which can suppress the reduction in the amount of reflected light caused by the weak responsiveness of the liquid crystal panel 20. This can improve the brightness of the projected image and prevent color mixing. In particular, reducing the light output of the light source 41 in the color mixing area between different colors can reliably reduce color mixing. In addition, converting the light output of the light source 41 to an off state to insert a black display into the color mixing area can more reliably prevent color mixing.

[0088] As a standard, controlling the light output in the time axis direction may be performed in proportion to the response waveform of the liquid crystal panel 20, and preferably, fine adjustment is ultimately performed in consideration of the balance between the brightness of the projected image and the color gamut reduction caused by color mixing.

[0089] In addition to this, the light output can be changed independently for each color of the light source 41 in accordance with the responsivity of the liquid crystal panel 20. Independently controlling the light output for each color in this manner also enables white balance adjustment to be performed.

[0090] [Example 2]

[0091] Embodiment 2 is a modified example of Embodiment 1, and is an embodiment in which light source control is performed in consideration of the temperature of the liquid crystal panel 20 (panel temperature). Figure 6 A system configuration example of a projection system according to Embodiment 2 is illustrated.

[0092] (System Configuration)

[0093] The responsiveness of the liquid crystal panel 20 changes due to the influence of the temperature dependency of the liquid crystal panel 20. Therefore, in the projection system 10 according to Embodiment 2, in consideration of the temperature of the liquid crystal panel 20, control is performed under the control of the light source control unit 431 so as to drive the light source 41 at a driving timing having a phase difference corresponding to the temperature of the liquid crystal panel 20 relative to the driving timing of the liquid crystal panel 20.

[0094] Specifically, if Figure 6 As shown in , the projection system 10 according to Embodiment 2 includes a temperature sensor 51 that detects (acquires) the temperature of the liquid crystal panel 20; and a memory 52 that stores a light source driving mode for the driving timing of the light source 41 with respect to the temperature of the driving timing of the liquid crystal panel 20 as a light source driving table. Then, the light source control unit 431 acquires the light source driving mode corresponding to the temperature detected by the temperature sensor 51 from the light source driving table stored in the memory 52 to change the light source driving mode, and drives the light source 41 based on the light source driving mode thus changed.

[0095] (Processing of changing light source driving mode)

[0096] use Figure 7 The flowchart in describes the process of changing the light source driving mode. Figure 7 0 is a flowchart illustrating the flow of the process of changing the light source driving mode. Note that the process of changing the light source driving mode is performed under the control of the system controller 43 including a microprocessor.

[0097] When the system controller 43 monitors the startup of the projection system 10 (step S11) and recognizes that the system is started (yes in S11), the system controller 43 obtains the detection voltage of the temperature sensor 51 (step S12), and then converts the detection voltage of the temperature sensor 51 into the temperature of the liquid crystal panel 20 (panel temperature) (step S13).

[0098] Next, the system controller 43 obtains the light source driving mode corresponding to the temperature of the liquid crystal panel 20 from the light source driving table stored in the memory 52 (step S14), and then sets the light source driving mode obtained from the light source driving table as the light source driving mode for driving the light source 41 in the light source control unit 43 (step S15).

[0099] Through the above-described processing, the light source driving mode set in the light source control unit 431 is changed to correspond to the temperature of the liquid crystal panel 20. The light source control unit 431 performs control of the light source 41 based on the light source driving mode thus changed. Figure 8 The result of the process of changing the light source driving mode is illustrated. Figure 8 The relationship between the intrinsic light emitting region and the light emitting region provided with a phase difference corresponding to the temperature of the liquid crystal panel 20 is illustrated.

[0100] As described above, in Embodiment 2, considering that the responsiveness of the liquid crystal panel 20 is changed by the influence of the temperature dependency of the liquid crystal panel 20, the light source 41 is driven with a driving timing having a phase difference corresponding to the temperature of the liquid crystal panel 20 relative to the driving timing of the liquid crystal panel 20. This makes it easier to balance the brightness and color mixing of the projected image than in Embodiment 1.

[0101] [Example 3]

[0102] Embodiment 3 is an improved example of Embodiment 1, and is an embodiment in which the light source control interval is variable along the time axis direction. Fig. 9 An explanatory diagram regarding a light source control interval according to Embodiment 3 is illustrated.

[0103] In Example 1, in the case where the light output of the light source 41 is controlled in a graded manner along the time axis direction, the light source control intervals are equal. In contrast, in Example 3, in the case where the light output of the light source 41 is controlled in a graded manner along the time axis direction, the light source control intervals are variable. More specifically, as Fig. 9 As shown in , in Example 3, when the light output of the light source 41 is controlled in a graded manner along the time axis direction, the light source control interval is narrower in the region X where the change of the response waveform of the liquid crystal panel 20 is steep than in the region outside the region X where the change is steep.

[0104] In the case where the light output of the light source 41 is controlled in a stepped manner along the time axis direction, the light source control interval is narrowed in the region X where the change in the response waveform of the liquid crystal panel 20 is steep, which can provide an ideal amount of light. The technology according to Embodiment 3 can also be applied to the projection system 10 according to Embodiment 2 that performs light source control in consideration of the temperature of the liquid crystal panel 20.

[0105] [Example 4]

[0106] Figure 4 is a system configuration example of a dual-panel type projection system according to an embodiment of the present disclosure. Fig.10 A system configuration diagram of a dual-panel type projection system according to Embodiment 4 is illustrated.

[0107] like Fig.10 As shown in , the projection system 10 according to Example 4 has a double-panel configuration including two liquid crystal panels 201 and 202 as display panels. Using the double-panel configuration, the projection system 10 according to Example 4 includes: an optical system including a light source 41 and a polarization beam splitter 53 between the two liquid crystal panels 201 and 202; and a projection optical system including a projection lens 21.

[0108] In the dual-panel type projection system 10 having the above-described configuration, in the case where the respective lights of R, G, and B are emitted from the optical system including the light source 41, for example, the respective lights of R and B pass through the polarization beam splitter 53 and are applied to the liquid crystal panel 201, while the respective lights of G and B are reflected by the polarization beam splitter 53 and are applied to the liquid crystal panel 202. Then, the respective lights of R and B modulated in the liquid crystal panel 201 are reflected by the polarization beam splitter 53 and enter the projection lens 21, while the respective lights of G and B modulated in the liquid crystal panel 202 pass through the polarization beam splitter 53 and enter the projection lens 21.

[0109] Even in the dual-panel type projection system 10 according to Embodiment 4, control similar to that in Embodiment 1 (i.e., graded control of the light output of each color of the light source 41 in the time axis direction according to the responsiveness of the liquid crystal panel 20) and control similar to that in Embodiment 3 (i.e., control for narrowing the light source control interval in the region where the change in the response waveform of the liquid crystal panel 20 is steep) can be performed. In the projection system 10 according to Embodiment 4, having a dual-panel configuration results in an increase in the number of color conversions compared to a single-panel configuration, which can further improve the brightness of the screen and further enhance the effect of preventing color mixing.

[0110] [Example 5]

[0111] Embodiment 5 is a modified example of Embodiment 4, and is an embodiment in which light source control is performed in consideration of the respective temperatures of the two liquid crystal panels 201 and 202 . Fig.11 A system configuration diagram of a projection system according to Embodiment 5 is illustrated.

[0112] The responsivity of the liquid crystal panel 201 and the responsivity of the liquid crystal panel 202 are respectively changed by the influence of the temperature dependence of the liquid crystal panel 201 and the temperature dependence of the liquid crystal panel 202. Therefore, in the projection system 10 according to Embodiment 5, in consideration of the respective temperatures of the liquid crystal panels 201 and 202, under the control of the light source control unit 431, control is performed so as to drive the light source 41 at a driving timing having a phase difference corresponding to the temperatures of the liquid crystal panels 201 and 202 with respect to the respective driving timings of the liquid crystal panels 201 and 202.

[0113] Specifically, if Fig.11As shown in , the projection system 10 according to Embodiment 5 includes temperature sensors 511 and 512 for respectively detecting (acquiring) the temperatures of the liquid crystal panels 201 and 202, and storing a light source driving mode for the driving timing of the light source 41 with respect to the temperature of the respective driving timings of the liquid crystal panels 201 and 202 as a light source driving table. Then, the light source control unit 431 acquires the light source driving mode corresponding to the respective temperatures detected by the temperature sensors 511 and 512 from the light source driving table stored in the memory 52 to change the light source driving mode, and drives the light source 41 based on the light source driving mode thus changed.

[0114] As described above, even in Embodiment 5, just like Embodiment 2, taking into account that the responsiveness of the liquid crystal panel 201 and the responsiveness of the liquid crystal panel 202 are changed by the influence of the temperature dependency of the liquid crystal panel 201 and the influence of the temperature dependency of the liquid crystal panel 202, respectively, the light source 41 is driven with a driving timing having a phase difference corresponding to the temperature of the liquid crystal panels 201 and 202 with respect to the respective driving timings of the liquid crystal panels 201 and 202. This makes it easier to balance the brightness and color mixing of the projected image than in Embodiment 4.

[0115] [Example 6]

[0116] Embodiment 6 is a modified example of Embodiment 4, and is an embodiment in which light source control is performed in consideration of the temperature of one of the two liquid crystal panels 201 and 202 . Fig.12 A system configuration diagram of a projection system according to Embodiment 6 is illustrated.

[0117] Embodiment 6 is an embodiment in the case where there is not much difference between the liquid crystal panels 201 and 202 in terms of the change in the responsivity of the liquid crystal panels 201 and 202 caused by temperature dependence. Therefore, the projection system 10 according to Embodiment 6 detects the temperature of one of the liquid crystal panels 201 and 202, and reflects the result of the detection in the light source control. Here, the temperature of the liquid crystal panel 201 is detected by the temperature sensor 511, and the light source driving mode corresponding to the result of the detection is obtained from the light source driving table stored in the memory 52 to change the light source driving mode. The light source 41 is driven based on the light source driving mode thus changed.

[0118] In the case where there is not much difference between the liquid crystal panels 201 and 202 in terms of the change in the responsivity of the liquid crystal panels 201 and 202 due to the temperature dependency, even in Embodiment 6, the brightness and color mixing of the projected image can be more easily balanced than in Embodiment 5. In addition, according to Embodiment 6, the components can be reduced and the control system can be simplified as compared with Embodiment 5. Here, the light source control is performed in consideration of the temperature of the liquid crystal panel 201, however, of course, the light source control can be performed in consideration of the temperature of the liquid crystal panel 202.

[0119] <Improvement example>

[0120] Although the technology of the present disclosure has been described with reference to preferred embodiments, the technology of the present disclosure is not limited to these embodiments. The configuration and structure of the projection system described in the above embodiments are illustrative and can be appropriately improved. For example, in the above embodiments, a projection system including a reflective liquid crystal panel as a display panel has been described as an example, however, the technology of the present disclosure can also be applied to a projection system including a transmissive liquid crystal panel.

[0121] In addition, in the above-mentioned embodiment, the projection system using LCOS as the light modulation element has been described as an example, however, the light modulation element is not limited to LCOS. Specifically, the technology of the present disclosure can also be applied to a projection system using HTPS (High Temperature Poly Silicon) or an element such as an electromagnetically driven micromirror (so-called MEMS mirror) using MEMS (Micro ElectroMechanical Systems) technology as a light modulation element.

[0122] <Possible Configurations of the Present Disclosure>

[0123] It is to be noted that the present disclosure may also have the following configurations.

[0124] 《A. Projection System》

[0125] [A-1]

[0126] A projection system, comprising:

[0127] A light source that outputs light in multiple colors;

[0128] A display panel including a light modulation element provided for each pixel and modulating light output from the light source;

[0129] a projection optical system that projects the light that has passed through the display panel; and

[0130] A controller controls the light output of each color of the light source along a time axis direction.

[0131] [A-2]

[0132] The projection system according to [A-1], wherein the display panel includes a liquid crystal panel including a liquid crystal element as the light modulation element.

[0133] [A-3]

[0134] The projection system according to [A-2], wherein the controller performs field sequential driving for color sequentially driving the light source in a time-division manner.

[0135] [A-4]

[0136] The projection system according to [A-3], wherein the controller controls the light output of each color of the light source along the time axis direction in a graded manner according to the responsiveness of the liquid crystal panel.

[0137] [A-5]

[0138] The projection system according to [A-4], wherein the controller reduces or turns off the light output between one color and another color of the light source.

[0139] [A-6]

[0140] The projection system according to [A-4], wherein the controller performs control of light output along a time axis direction so as to be proportional to a response waveform of the liquid crystal panel.

[0141] [A-7]

[0142] The projection system according to [A-4], wherein the controller independently changes the light output for each color of the light source according to the responsiveness of the liquid crystal panel.

[0143] [A-8]

[0144] A projection system according to any one of [A-1] to [A-7], wherein the controller drives the light source in a light source driving mode, and the driving timing of the light source driving mode has a phase difference corresponding to the temperature of the liquid crystal panel relative to the driving timing of the liquid crystal panel.

[0145] [A-9]

[0146] The projection system according to [A-8], comprising:

[0147] a temperature sensor for detecting the temperature of the liquid crystal panel; and

[0148] a memory storing a light source driving pattern for a driving timing of the light source relative to a temperature of a driving timing of the liquid crystal panel as a light source driving table, wherein

[0149] The controller acquires a light source driving mode corresponding to the temperature detected by the temperature sensor from the light source driving table, and drives the light source based on the light source driving mode thus acquired.

[0150] [A-10]

[0151] The projection system according to any one of [A-1] to [A-9], wherein the controller makes the light source control interval along the time axis direction controllable.

[0152] [A-11]

[0153] The projection system according to [A-10], wherein the controller makes the light source control interval narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

[0154] [A-12]

[0155] The projection system according to any one of [A-1] to [A-11], wherein the display panel has a double panel configuration provided with two liquid crystal panels.

[0156] The projection system according to [A-12], comprising:

[0157] a temperature sensor for detecting a temperature of at least one of the two liquid crystal panels; and

[0158] a memory storing a light source driving pattern for a driving timing of the light source with respect to a temperature of a driving timing of the two liquid crystal panels as a light source driving table, wherein

[0159] The controller acquires a light source driving mode corresponding to a temperature detected by a temperature sensor provided in at least one of the two liquid crystal panels from the light source driving table, and drives the light source on the basis of the light source driving mode thus acquired.

[0160] 《B. Control method of projection system》

[0161] [B-1]

[0162] A control method for a projection system, the projection system comprising:

[0163] A light source that outputs light in multiple colors;

[0164] a display panel including a light modulation element provided for each pixel and modulating light output from the light source; and

[0165] a projection optical system that projects the light that has passed through the display panel,

[0166] The control method comprises:

[0167] When controlling the projection system, the light output of each color of the light source is controlled along the time axis direction.

[0168] [B-2]

[0169] The control method of the projection system according to [B-1], wherein the display panel includes a liquid crystal panel including a liquid crystal element as the light modulation element.

[0170] [B-3]

[0171] According to the control method of the projection system described in [B-2], field sequential driving for color sequentially driving the light source in a time-division manner is performed.

[0172] [B-4]

[0173] According to the control method of the projection system described in [B-3], the light output of each color of the light source is controlled in a graded manner along the time axis direction according to the responsiveness of the liquid crystal panel.

[0174] [B-5]

[0175] The control method of the projection system according to [B-4], wherein the light output between one color and another color of the light source is reduced or turned off.

[0176] [B-6]

[0177] According to the control method of the projection system described in [B-4], the control of the light output in the time axis direction is performed so as to be proportional to the response waveform of the liquid crystal panel.

[0178] [B-7]

[0179] The control method of the projection system according to [B-4], wherein the light output is changed independently for each color of the light source according to the responsiveness of the liquid crystal panel.

[0180] [B-8]

[0181] According to the control method of the projection system described in any one of [B-1] to [B-7], the light source is driven in a light source driving mode, and the driving timing of the light source driving mode has a phase difference corresponding to the temperature of the liquid crystal panel relative to the driving timing of the liquid crystal panel.

[0182] [B-9]

[0183] According to the control method of the projection system described in [B-8], in which a temperature sensor and a memory are included, the temperature sensor detects the temperature of the liquid crystal panel, the memory stores a light source driving mode for the temperature of the driving timing of the light source relative to the driving timing of the liquid crystal panel as a light source driving table, the light source driving mode corresponding to the temperature detected by the temperature sensor is obtained from the light source driving table, and the light source is driven based on the light source driving mode obtained thereby.

[0184] [B-10]

[0185] The method for controlling a projection system according to any one of [B-1] to [B-9], wherein the light source control interval along the time axis direction is controllable.

[0186] [B-11]

[0187] The control method of a projection system according to [B-10], wherein the light source control interval is narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

[0188] [B-12]

[0189] The control method of a projection system according to any one of [B-1] to [B-11], wherein the display panel has a double panel configuration provided with two liquid crystal panels.

[0190] [B-13]

[0191] According to the control method of the projection system described in [B-12], in which a temperature sensor and a memory are included, the temperature sensor detects the temperature of at least one of the two liquid crystal panels, the memory stores a light source driving mode for the driving timing of the light source relative to the temperature of the driving timing of the two liquid crystal panels as a light source driving table, the light source driving mode corresponding to the temperature detected by the temperature sensor provided in at least one of the two liquid crystal panels is obtained from the light source driving table, and the light source is driven based on the light source driving mode obtained thereby.

[0192] Reference numerals

[0193] 10 Projection System

[0194] 11R,11G,11B solid state light source

[0195] 13,14 Dichroic Mirror

[0196] 16 Rod Integrator

[0197] 19 Total reflection prism

[0198] 20,201,202 LCD Panel

[0199] 21 Projection lens

[0200] 30 Screen

[0201] 41 Light source (light source unit)

[0202] 42 Image Processing Engine

[0203] 43 System Controller

[0204] 44 Light source drive unit

[0205] 51 Temperature sensor

[0206] 52 Memory

[0207] 53 Polarization beam splitter

[0208] 431 Light source control unit

Claims

1. A projection system, comprising: a light source that outputs light in a plurality of colors; a liquid crystal panel including a light modulation element provided for each pixel and including a liquid crystal element that modulates light output from the light source as the light modulation element; a projection optical system that projects the light that has passed through the liquid crystal panel; and A controller controls the light output of each color of the light source along the time axis direction, wherein The controller performs field sequential driving for color sequentially driving the light source in a time division manner, and controls the light output of each color of the light source along the time axis direction in a graded manner according to the responsiveness of the liquid crystal panel, and The controller makes the light source control interval along the time axis direction controllable and makes the light source control interval narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

2. The projection system of claim 1, wherein the controller reduces or shuts off the light output of the light source between one color and another color.

3. The projection system according to claim 1, wherein the controller controls the light output along a time axis direction to be proportional to a response waveform of the liquid crystal panel. 4 . The projection system of claim 1 , wherein the controller independently changes the light output for each color of the light source according to the responsiveness of the liquid crystal panel. 5 . The projection system according to claim 1 , wherein the controller drives the light source in a light source driving mode, a driving timing of the light source driving mode having a phase difference corresponding to a temperature of the liquid crystal panel with respect to a driving timing of the liquid crystal panel.

6. The projection system according to claim 5, comprising: A temperature sensor, which detects the temperature of the liquid crystal panel; and a memory storing a light source driving pattern for a driving timing of the light source with respect to a temperature of a driving timing of the liquid crystal panel as a light source driving table, wherein The controller acquires a light source driving mode corresponding to the temperature detected by the temperature sensor from the light source driving table, and drives the light source based on the light source driving mode thus acquired.

7. The projection system according to claim 1, wherein the display panel has a dual panel configuration provided with two liquid crystal panels.

8. The projection system according to claim 7, comprising: a temperature sensor for detecting a temperature of at least one of the two liquid crystal panels; and A memory storing a light source driving pattern for a driving timing of the light source with respect to a temperature of a driving timing of the two liquid crystal panels as a light source driving table, wherein The controller acquires a light source driving mode corresponding to a temperature detected by a temperature sensor provided in at least one of the two liquid crystal panels from the light source driving table, and drives the light source based on the light source driving mode thus acquired.

9. A projection system comprising: a light source that outputs light in a plurality of colors; a liquid crystal panel including a light modulation element provided for each pixel and including a liquid crystal element that modulates light output from the light source as the light modulation element; a projection optical system that projects the light that has passed through the liquid crystal panel; and A controller controls the light output of each color of the light source along the time axis direction, wherein The controller makes the light source control interval along the time axis direction controllable and makes the light source control interval narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

10. A method for controlling a projection system, the projection system comprising: a light source that outputs light in a plurality of colors; a liquid crystal panel including a light modulation element provided for each pixel and including a liquid crystal element that modulates light output from the light source as the light modulation element; and a projection optical system that projects the light that has passed through the liquid crystal panel, The projection system controls the light output of each color of the light source along the time axis direction, and makes the light source control interval along the time axis direction controllable, The control method comprises: When controlling the projection system, Performing field sequential driving for color sequentially driving the light source in a time-division manner; controlling the light output of each color of the light source along the time axis direction in a graded manner according to the responsiveness of the liquid crystal panel; and The light source control interval is made narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

11. A method for controlling a projection system, the projection system comprising: a light source that outputs light in a plurality of colors; a liquid crystal panel including a light modulation element provided for each pixel and including a liquid crystal element that modulates light output from the light source as the light modulation element; and a projection optical system that projects the light that has passed through the liquid crystal panel, The projection system controls the light output of each color of the light source along the time axis direction, and makes the light source control interval along the time axis direction controllable, The control method comprises: In controlling the projection system, the light source control interval is made narrower in a region where a change in a response waveform of the liquid crystal panel is steep than in another region.

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