Illumination system, illumination control method and projection apparatus

An illumination system including a first laser light source, a second laser light source, and a wavelength conversion module is provided. The first laser light source provides a first laser light beam in a first time interval and a third time interval. The wavelength conversion module is located on a transmission path of the first laser light beam. The wavelength conversion module includes at least one wavelength conversion region, at least one non-conversion region, a first standby region, and a second standby region, and is configured to rotate along a rotating shaft, so that the wavelength conversion region, the first standby region, the non-conversion region, and the second standby region are sequentially rotated in one direction, and the wavelength conversion region and the non-conversion region are alternately cut into the transmission path of the first laser light beam. An illumination control method and a projection apparatus are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 202010089823.1, filed on Feb. 13, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The invention relates to an optical system, an optical control method, and an optical apparatus, and particularly relates to an illumination system, an illumination control method, and a projection apparatus.

Description of Related Art

Recently, projection apparatuses based on solid-state light sources such as light-emitting diodes (LEDs) and laser diodes have gradually gained a place in the market. Generally, excitation light of the solid-state light sources is converted by a wavelength conversion material on a wavelength conversion module in a projection apparatus to generate converted light of different colors. In addition, in order to meet requirements on color performance, a filter module is placed on a rear light path of the projection apparatus, and the filter module filters the converted light of the wavelength conversion module to produce color light of predetermined colors. The color light is modulated by a light valve to produce an image light beam for projecting to external.

Generally, since a wavelength conversion element of the wavelength conversion module has a boundary of a wavelength conversion region and a non-conversion region, when the excitation light is incident to a region near the boundary, and a part of the excitation light is in the wavelength conversion region and a part of the excitation light is in the non-conversion region, such state is generally referred to as a spoke state, which may result in a phenomenon of image discoloration. This is because that the wavelength conversion element is continually rotated, and a ratio of the excitation light incident to the wavelength conversion region and incident to the non-conversion region is changed along with time, so that a light beam emitted from the wavelength conversion element may form converted light and non-converted light with unstable intensity. Therefore, when the wavelength conversion element is rotated to the spoke state, the light valve in operation in the projection apparatus is temporarily turned off to avoid producing image discoloration. However, in this way, the projection apparatus may lose brightness of a display image.

Moreover, in order to improve a color update rate of the projection apparatus to reduce a color break issue in human visual perception, and achieve smoother viewing quality, technical measures taken by the known projection apparatuses are mostly to increase a number of rotations of the wavelength conversion element and increase a number of divisions of the wavelength conversion regions and the non-conversion regions on the wavelength conversion element. However, in this way, while the number of divisions of the wavelength conversion regions and the non-conversion regions are increased, a frequency of passing through the spoke state is also increased. Therefore, in order to maintain a certain brightness of the display image, the color update rate and the number of the wavelength conversion regions and the non-conversion regions of the projection apparatus have to be limited.

SUMMARY

The invention is directed to an illumination system, which is adapted to provide display images with good quality.

The invention is directed to a projection apparatus, which is adapted to provide display images with good quality.

The invention is directed to an illumination control method, which controls the projection apparatus to provide display images with good quality.

Other objects and advantages of the invention may be further illustrated by the technical features broadly embodied and described as follows.

In order to achieve one or a portion of or all of the objects or other objects, an embodiment of the invention provides an illumination system. The illumination system is configured to provide an illumination light beam, and the illumination system includes a first laser light source, a second laser light source, and a wavelength conversion module. The first laser light source provides a first laser light beam in a first time interval and a third time interval. The second laser light source provides a second laser light beam in a second time interval and a fourth time interval. The wavelength conversion module is located on a transmission path of the first laser light beam, and the wavelength conversion module has at least one wavelength conversion region and at least one non-conversion region. A first standby region and a second standby region are formed between the at least one wavelength conversion region and the at least one non-conversion region. The wavelength conversion module is configured to rotate along a rotating shaft, so that the at least one wavelength conversion region, the first standby region, the at least one non-conversion region, and the second standby region are sequentially rotated in one direction, and the at least one wavelength conversion region and the at least one non-conversion region are alternately cut into the transmission path of the first laser light beam. When the wavelength conversion module is rotated, in the first time interval, the first laser light beam is incident to the at least one non-conversion region of the wavelength conversion module to form first color light, in the second time interval and the fourth time interval, the second laser light beam forms second color light, and in the third time interval, the first laser light beam is incident to the wavelength conversion region of the wavelength conversion module to form third color light, and in the second time interval and the fourth time interval, the first standby region and the second standby region are respectively cut into the transmission path of the first laser light beam formed in the first time interval or the third time interval, and no light spot is formed on the wavelength conversion module by the first laser light beam.

In order to achieve one or a portion of or all of the objects or other objects, an embodiment of the invention provides a projection apparatus. The projection apparatus includes the aforementioned illumination system, a light valve and a projection lens. The light valve is located on a transmission path of the illumination light beam and is configured to convert the illumination light beam into an image light beam. The projection lens is located on a transmission path of the image light beam and is configured to project the image light beam out of the projection apparatus.

In order to achieve one or a portion of or all of the objects or other objects, an embodiment of the invention provides an illumination control method. The illumination control method is configured to control an illumination system in a projection apparatus. The illumination system includes a first laser light source, a second laser light source, and a wavelength conversion module. The first laser light source is configured to provide a first laser light beam, the second laser light source is configured to provide a second laser light beam, and the wavelength conversion module is located on a transmission path of the first laser light beam and has at least one wavelength conversion region and at least one non-conversion region. A first standby region and a second standby region are formed between the at least one wavelength conversion region and the at least one non-conversion region. The wavelength conversion module is configured to rotate along a rotating shaft, so that the at least one wavelength conversion region, the first standby region, the at least one non-conversion region, and the second standby region are sequentially rotated in one direction, and the at least one wavelength conversion region and the at least one non-conversion region are alternately cut into the transmission path of the first laser light beam. The illumination control method includes following steps. In a first time interval, the first laser light source is turned on, and the second laser light source is turned off, wherein the first laser light beam is incident to the at least one non-conversion region of the wavelength conversion module to form first color light. In a second time interval, the second laser light source is turned on, and the first laser light source is turned off, wherein the second laser light beam forms second color light, the first standby region is cut into the transmission path of the first laser light beam formed in the first time interval or a third time interval, and no light spot is formed on the wavelength conversion module by the first laser light beam. In the third time interval, the first laser light source is turned on, and the second laser light source is turned off, wherein the first laser light beam is incident to the at least one wavelength conversion region of the wavelength conversion module to form third color light. In a fourth time interval, the second laser light source is turned on, and the first laser light source is turned off, wherein the second laser light beam forms the second color light, the second standby region is cut into the transmission path of the first laser light beam formed in the first time interval or the third time interval, and no light spot is formed on the wavelength conversion module by the first laser light beam.

Based on the above description, the embodiments of the invention have at least one of following advantages or effects. In the embodiments of the invention, the illumination system and the projection apparatus are capable of producing the required color light at different time intervals through arrangement of the first laser light source, the second laser light source, and the wavelength conversion module. In this way, the phenomenon of image discoloration caused by the spoke state is prevented, and the brightness of the display image is maintained. Moreover, arrangement of a filter module in the projection apparatus and the illumination system may be omitted, so that the loss of brightness is reduced, and a 100% RGB color light output ratio (CLO) is achieved. Moreover, in the embodiments of the invention, the illumination system and the projection apparatus may adopt the illumination control method to simply switch a turn-on or turn-off state of the first laser light source and the second laser light source without limitation, so as to improve the color update rate of the projection apparatus and eliminate the color break issue to achieve smooth viewing quality.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a structural schematic diagram of a projection apparatus according to an embodiment of the invention.FIG. 2Ais a top view of a wavelength conversion module ofFIG. 1.FIG. 2Bis a relationship diagram of transmittances of a first light splitting element ofFIG. 1to light of different wavebands.FIG. 2Cis a relationship diagram of transmittances of a second light splitting element ofFIG. 1to light of different wavebands.FIG. 2Dis a timing schematic diagram of a first laser light source, a second laser light source, a wavelength conversion module and a light valve ofFIG. 2Ain different time intervals. Referring toFIG. 1, a projection apparatus200includes an illumination system100, a light valve210, and a projection lens220. The illumination system100is adapted to provide an illumination light beam70. The light valve210is disposed on a transmission path of the illumination light beam70, and is adapted to convert the illumination light beam70into an image light beam80. The projection lens220is disposed on a transmission path of the image light beam80, and is adapted to project the image light beam80out of the projection apparatus200to form an image. In the embodiment, a number of the light valve210is one, but the invention is not limited thereto, and in other embodiments, the number of the light valves210may be plural. Moreover, in the embodiment, the light valve210may be a digital micro-mirror device (DMD) or a liquid crystal-on-silicon panel (LCOS panel). However, in other embodiments, the light valve210may also be a transmissive liquid crystal panel or other light beam modulators.

To be specific, as shown inFIG. 1, in the embodiment, the illumination system100includes a first laser light source110B, a second laser light source110R, a wavelength conversion module120, a light splitting and combining module130, and a light uniforming element140. Further, as shown inFIG. 2D, in the embodiment, the first laser light source110B is turned on during a first time interval T1and a third time interval T3and is turned off during a second time interval T2and a fourth time interval T4. The second laser light source110R is turned off during the first time interval T1and the third time interval T3and is turned on during the second time interval T2and the fourth time interval T4. In this way, as shown inFIG. 1andFIG. 2D, the first laser light source110B may provide a first laser light beam50B during the first time interval T1and the third time interval T3. The second laser light source110R may provide a second laser light beam50R during the second time interval T2and the fourth time interval T4. For example, in the embodiment, the first laser light beam50B is a blue laser light beam, and the second laser light beam50R is a red laser light beam. For example, in the embodiment, the first laser light source110B may include one or a plurality of blue laser diodes arranged in an array, and the second laser light source110R may include one or a plurality of red laser diodes arranged in an array, but the invention is not limited thereto.

To be specific, as shown inFIG. 1, in the embodiment, the light splitting and combining module130includes a first light splitting element131, light transmitting elements LT and a second light splitting element132. The light splitting and combining module130is located on transmission paths of the first laser light beam50B and the second laser light beam50R, and the first light splitting element131is disposed corresponding to the first laser light source110B and is located between the first laser light source110B and the wavelength conversion module120. For example, as shown inFIG. 2B, in the embodiment, the first light splitting element131may, for example, reflect light with a waveband within a range of 480 to 590 nm, and is pervious to light with a waveband less than 480 nm or greater than 590 nm. In other words, the first light splitting element131is, for example, a dichroic mirror with green reflection, which is pervious to blue and red light and provides a reflection effect to green light. Therefore, the first light splitting element131is pervious to the blue first laser light beam50B. In this way, the first laser light beam50B of the first laser light source110B may be transmitted to the wavelength conversion module120by penetrating through the first light splitting element131.

On the other hand, as shown inFIG. 1, in the embodiment, the second light splitting element132of the light splitting and combining module130is located between the second laser light source110R and the first light splitting element131, and the light transmitting elements LT are located between the wavelength conversion module120and the second light splitting element132. For example, as shown inFIG. 2C, in the embodiment, the second light splitting element132may be, for example, pervious to light with a waveband within a range of 470 to 600 nm, and reflect light with a waveband less than 470 nm. In other words, the second light splitting element132is, for example, a dichroic mirror with blue reflection, which provides a reflection effect to blue light, and is pervious to light of other colors (for example, red light and yellow light). The light transmitting elements LT may provide a reflection effect to visible light, and in the embodiment ofFIG. 1, the light transmitting elements LT are, for example, reflectors or other reflecting elements.

Further, as shown inFIG. 1andFIG. 2A, in the embodiment, the wavelength conversion module120is located on the transmission path of the first laser light beam50B and is adapted to rotate. Furthermore, as shown inFIG. 1andFIG. 2A, the wavelength conversion module120includes a rotating shaft121and a substrate122. The rotating shaft121is connected to the substrate122, and is configured to drive the substrate122to rotate along the rotating shaft121. The wavelength conversion module120is disposed on the transmission path of the first laser light beam50B, and the wavelength conversion module120is configured with at least one non-conversion region NT and at least one wavelength conversion region WR on the substrate122. For example, as shown inFIG. 2A, in the embodiment, an area of the at least one non-conversion region NT is the same as an area of the at least one wavelength conversion region WR, but the invention is not limited thereto. In other embodiments that are not shown, the area of the at least one non-conversion region NT and the area of the at least one wavelength conversion region WR may also be different.

To be specific, in the embodiment, the at least one non-conversion region NT of the wavelength conversion module120is respectively formed by a light-transmitting layer. Namely, in the embodiment, the at least one non-conversion region NT is a light penetration region, and when the at least one non-conversion region NT is located on the transmission path of the first laser light beam50B, the first laser light beam50B may pass through the at least one non-conversion region NT to form first color light70B through subsequent optical elements. On the other hand, the at least one wavelength conversion region WR of the wavelength conversion module120is respectively formed by a wavelength conversion layer, which is configured to convert the first laser light beam50B into a wavelength-converted light beam60Y. For example, in the embodiment, a wavelength conversion material may include phosphor powder adapted to be excited to produce a yellow light beam. Therefore, when the at least one wavelength conversion region WR is located on the transmission path of the first laser light beam50B, the wavelength conversion material is irradiated by the laser light beam50B to form the wavelength-converted light beam60Y, which is yellow light.

Further, as shown inFIG. 2A, a first standby region IB1and a second standby region IB2are formed between the at least one wavelength conversion region WR and the at least one non-conversion region NT. As shown inFIG. 2A, a number of the at least one wavelength conversion region WR and a number of the at least one non-conversion region NT of the wavelength conversion module120are respectively one. When the wavelength conversion module120is rotated along the rotating shaft121, the wavelength conversion region WR, the first standby region IB1, the non-conversion region NT and the second standby region IB2are sequentially rotated in a direction CW. For example, in the embodiment, the direction CW is a clockwise direction. Moreover, for example, in the embodiment, the first standby region IB1or the second standby region IB2may be a boundary region including the wavelength conversion region WR or the non-conversion region NT. To be specific, in the embodiment, as shown inFIG. 2A, the first standby region IB1includes a first boundary B1of one end of the wavelength conversion region WR and one end of the non-conversion region NT connected thereto. The second standby region IB2includes a second boundary B1of the other end of the wavelength conversion region WR and the other end of the non-conversion region NT connected thereto.

Further, as shown inFIG. 2AandFIG. 2D, in the embodiment, when the wavelength conversion module120is rotated along the rotating shaft121, in the second time interval T2, a part of the non-conversion region NT adjacent to the first boundary B1, the first boundary B1, and a part of the wavelength conversion region WR adjacent to the first boundary B1are sequentially cut into the transmission path of the first laser light beam50B formed during a turn-on time interval of the first laser light source110B (i.e., the first time interval T1or the third time interval T3). In the fourth time interval T4, a part of the wavelength conversion region WR adjacent to the second boundary B2, the second boundary B2, and a part of the non-conversion region NT adjacent to the second boundary B2are sequentially cut into the transmission path of the first laser light beam50B formed during the turn-on time interval of the first laser light source110B (i.e., the first time interval T1or the third time interval T3).

To be specific, in the embodiment, the first standby region IB1or the second standby region IB2may be an imaginary virtual region, and a corresponding position thereof is a position where the wavelength conversion module120is cut into the transmission path of the first laser light beam50B formed in the first time interval T1and the third time interval T3at a timing when the first laser light source110B is turned off (i.e., the second time interval T2and the fourth time interval T4). Namely, the illumination system100may control a timing when the first standby region IB1or the second standby region IB2of the wavelength conversion module120is cut into the transmission path of the first laser light beam50B corresponding to the second time interval T2and the fourth time interval T4. In the second time interval T2and the fourth time interval T4, the corresponding first standby region IB1and the second standby region IB2are cut into the transmission path of the first laser light beam50B. However, since the first laser light source110B is turned off at this moment, no first laser light beam50B passes through the first standby region IB1or the second standby region IB2of the wavelength conversion module120, and no light spot is formed on the wavelength conversion module120by the first laser light beam50B, and thus no phenomenon of image discoloration caused by the spoke state is generated, so that the projection apparatus200does not need to turn off the light valve210in order to reduce the phenomenon of image discoloration during the operation of the light valve210, and therefore the brightness of the display image may be maintained.

Further, as shown inFIG. 1,FIG. 2A, andFIG. 2D, in the first time interval T1, the first laser light beam50B forms a light spot on the wavelength conversion module120, and the light spot is completely located on the non-conversion region NT, i.e., the first laser light beam50B may pass through the non-conversion region NT, and is sequentially transmitted to the second light splitting element132and the first light splitting element131through the light transmitting elements LT to form the first color light70B. On the other hand, as shown inFIG. 1andFIG. 2D, in the second time interval T2and the fourth time interval T4, since the second laser light source110R is turned on, the second laser light beam50R provided by the second laser light source110R may pass through the second light splitting element132and is transmitted to the first light splitting element131to form second color light70R, where the second color light70R is, for example, red light.

Moreover, in the third time interval T3, the first laser light beam50B forms a light spot on the wavelength conversion module120, and the light spot is completely located on the wavelength conversion region WR. In this way, the wavelength conversion module120may convert the first laser light beam50B into the wavelength-converted light beam60Y of the yellow color through the wavelength conversion material, and transmit the wavelength-converted light beam60Y to the first light splitting element131, and the wavelength-converted light beam60Y is filtered into third color light70G with a narrow spectrum range by the first light splitting element131, where the wavelength conversion material includes, for example, phosphor powder that may be excited to produce a yellow light beam, the wavelength-converted light beam60Y is, for example, yellow light, and the third color light70G is, for example, green light. Moreover, since human eyes are more sensitive to the green light, when a purity or brightness of the green light is increased, the human eyes may also perceive that the brightness of the display image becomes brighter. In this way, the illumination system100and the projection apparatus200may obtain the third color light70G (the green light) with the narrow spectrum range (i.e., the purity is higher) by configuring the first light splitting element131, so as to help improving the brightness of the display image perceived by human eyes.

On the other hand, as shown inFIG. 1, in the embodiment, the illumination system100may further selectively include an optical uniforming unit OU, and the optical uniforming unit OU is located on the transmission path of the first laser light beam50B and the second laser light beam50R, and is located between the first light splitting element131and the second light splitting element132. For example, the optical uniforming unit OU may include a light diffusing element, a polarizing element, or a combination of the light diffusing element and the polarizing element.

Further, when the optical uniforming unit OU includes a light diffusing element, the first laser light beam50B and the second laser light beam50R may have a light diffusion effect after passing through the rotated optical uniforming unit OU, and the laser spot is accordingly eliminated. When the optical uniforming unit OU includes a polarizing element, the first laser light beam50B and the second laser light beam50R may have different polarization states at different times after passing through the rotated optical uniforming unit OU. In this way, the illumination system100may be applied to the projection apparatus200equipped with a polarization stereo mode, so as to eliminate a phenomenon of uneven image color or uneven brightness often occurred in the projection apparatus200equipped with the polarization stereo mode.

For example, in a known framework of the illumination system100, polarization of a laser light beam may be destroyed by other internal optical elements, which causes disorder of a polarization direction and intensity of the laser light beam, and causes the problem of uneven brightness of the display image of the projection apparatus200equipped with the polarization stereo mode. However, in the illumination system100of the embodiment, since the illumination light beam70and the image light beam80formed by the first laser light beam50B and the second laser light beam50R may have different polarization states at different times, light spots of different polarization states may be formed along with different time points. Due to the effect of visual persistence, a brightness of the light spot on an illuminated surface observed by the human eye is a superimposed brightness of light spots of different time points within a visual persistence time, so that the light spots of different time points within the visual persistence time may also produce a light spot with uniform brightness after superposition, the color or brightness of the display image viewed by the user is uniform, and the user may view a stereoscopic display image with better uniformity.

Then, as shown inFIG. 1, the first color light70B, the second color light70R, and the third color light70G are transmitted to the first light splitting element131to form an illumination light beam70. Moreover, in the embodiment, the first color light70B is blue light, the second color light70R is red light, and the third color light70G is green light. Namely, through arrangement of the first laser light source110B, the second laser light source110R, and the wavelength conversion module120, the illumination system100may produce the illumination light beam70containing the RGB color light. Therefore, in the projection apparatus200and the illumination system100, configuration of a filter module (a filter wheel) may be omitted, so as to reduce the loss of brightness, and achieve 100% RGB color light output ratio (CLO ratio).

Then, as shown inFIG. 1, in the embodiment, the light uniforming element140is located on a transmission path of the illumination light beam70. In the embodiment, the light uniforming element140includes an integration rod, but the invention is not limited thereto. In more detail, as shown inFIG. 1, when the illumination light beam70is transmitted to the light uniforming element140, the light uniforming element140uniforms the illumination light beam70and transmits the uniformed illumination light beam70to the light valve210.

Then, as shown inFIG. 1, the light valve210is located on a transmission path of the illumination light beam70coming from the light uniforming element140, and is configured to convert the illumination light beam70into the image light beam80. The projection lens220is located on a transmission path of the image light beam80, and is configured to project the image light beam80out of the projection apparatus200to form an image. After the illumination light beam70is converged on the light valve210, the light valve210may sequentially convert the illumination light beam70into the image light beams80of different colors for transmitting to the projection lens220. Therefore, the image formed by projecting the image light beam80converted by the light valve210may be a color image.

Furthermore, in the embodiment, the first color light70B is blue light, the second color light70R is red light, and the third color light70G is green light, and since the illumination light beam70is formed by mixing the first color light70B, the second color light70R and the third color light70G, a hue or color temperature of the illumination light beam70may be determined by a proportional relationship of the first color light70B, the second color light70R and the third color light70G, and a hue or color temperature of the image light beam80formed by the illumination light beam70is also determined by the above proportional relationship.

To be specific, when a proportion of blue light of the illumination light beam70increases, the color temperature of the illumination light beam70also increases. For example, a ratio of a time length of the third time interval T3to a time length of the first time interval T1is between 2 and 4, and a ratio of a time length of the second time interval T2or the fourth time interval T4to the time length of the first time interval T1is between 1 and 2.5. In this way, in the embodiment, the projection apparatus200and the illumination system100may adjust relative proportions of the first color light70B, the second color light70R, and the third color light70G of the illumination light beam70through time lengths of turn-on time intervals of the first laser light source110B and the second laser light source110R and the configuration of the wavelength conversion region WR and the non-conversion region NT of the wavelength conversion module120. Therefore, the illumination system100and the projection apparatus200may adjust the color temperature of the image light beam80without adjusting the intensity of the first laser light source110B or the second laser light source110R, thereby preventing loss of the brightness of the display image.

In this way, the illumination system100and the projection apparatus200may produce the required color light in different time intervals through arrangement of the first laser light source110B, the second laser light source110R, and the wavelength conversion module120, and the phenomenon of image discoloration caused by the spoke state may be prevented, and the brightness of the display image is maintained. Moreover, in the projection apparatus200and the illumination system100, arrangement of a filter module may be omitted, so as to reduce the loss of brightness, and achieve the 100% RGB color light output ratio.

FIG. 3AandFIG. 3Bare top views of different wavelength conversion modules ofFIG. 1. Referring toFIG. 3AandFIG. 3B, a wavelength conversion module320A and a wavelength conversion module320B ofFIG. 3AandFIG. 3Bare similar to the wavelength conversion module120ofFIG. 2A, and differences there between are as follows. In the embodiment ofFIG. 2A, only one non-conversion region NT and one wavelength conversion region WR of the wavelength conversion module120are taken as an example for description, but the invention is not limited thereto. In the embodiment ofFIG. 3A, the number the non-conversion regions NT and the number of the wavelength conversion regions WR in the wavelength conversion module320A may be respectively two, and in the embodiment ofFIG. 3B, the number the non-conversion regions NT and the number of the wavelength conversion regions WR in the wavelength conversion module320B may be respectively three. In more detail, one end of a wavelength conversion region WR and one end of a non-conversion region NT connected to the above end are a first boundary B1, the first standby region IB1includes the first boundary B1, and the other end of the wavelength conversion region WR and one end of another non-conversion region NT connected to the other end are a second boundary B2, and the second standby region IB2includes the second boundary B2; and the other end of the other non-conversion region NT and one end of another wavelength conversion region WR connected to the other end are defined as another first boundary B1. According to the above definition, when the number of the non-conversion regions NT and the number of the wavelength conversion regions WR of the wavelength conversion module320are increased, the numbers of the corresponding first standby regions IB1and the second standby regions IB2are also increased, so that a switching frequency of the first laser light source110B and the second laser light source110R is also increased, i.e., a length of a switching time is accordingly reduced, which is equivalent to that a cycle time length of the light valve210in forming the image light beam80with the blue light, the red light and the green light is accordingly shortened. In this way, a color update rate of an image produced by the projection apparatus200using the aforementioned wavelength conversion module320A or the wavelength conversion module320B may also be increased accordingly to avoid the color break issue and achieve smoother viewing quality. However, due to various limitations such as a swing rate of the light valve210, a switching response time of the first laser light source110B and the second laser light source110R, and the non-conversion region NT and the wavelength conversion region WR of the wavelength conversion module are required to be larger than a size of a laser light spot, in other embodiments of the invention, the number of the non-conversion regions NT and the number of the wavelength conversion regions WR in the wavelength conversion module may be respectively increased to about ten.

Moreover, in the embodiment, although the situation that the first standby region IB1and the second standby region IB2are formed between the non-conversion region NT and the wavelength conversion region WR is taken as an example for description, the invention is not limited thereto. In another embodiment that is not shown, when the wavelength conversion module has a plurality of wavelength conversion regions WR, and two different wavelength conversion regions WR are adjacent to each other, the first standby region IB1or the second standby region IB2may also be configured between the two wavelength conversion regions WR to eliminate the phenomenon of image discoloration caused by the spoke state.

In this way, when the aforementioned illumination system100and the projection apparatus200adopt the wavelength conversion module320A ofFIG. 3Aor the wavelength conversion module320B ofFIG. 3B, besides similar effects and advantages as that of the aforementioned illumination system100and the projection apparatus200are achieved by achieving the configuration of the first standby region IB1or the second standby region IB2, the number of the non-conversion regions NT and the wavelength conversion regions WR of the wavelength conversion module and the number of the corresponding first standby regions IB1and the second standby regions IB2may be selectively designed according to user requirements on viewing quality to meet an actual requirement on the color update rate. In this way, in the embodiments of the invention, the illumination system100and the projection apparatus200may adopt the illumination control method to simply switch the turn-on or turn-off state of the first laser light source110B and the second laser light source110R without limitation, so as to improve the color update rate of the projection apparatus200and eliminate the color break issue to achieve smoother viewing quality.

On the other hand, in the aforementioned embodiments, although the situation that the first standby region IB1or the second standby region IB2is the boundary region including the wavelength conversion region WR or the non-conversion region NT is taken as an example for description, the invention is not limited thereto. In other embodiments, the first standby region IB1or the second standby region IB2may also be a region on the substrate122where the wavelength conversion region WR or the non-conversion region NT is not actually arranged. By referring to the invention, any person skilled in the art may make appropriate modifications to the configuration structure of the first standby region IB1or the second standby region IB2to achieve the similar effects and advantages as that of the aforementioned projection apparatus200, which is still considered to be within the scope of the invention. Some other embodiments are provided below for further description.

FIG. 4AtoFIG. 4Care top views of different wavelength conversion modules ofFIG. 1. Referring toFIG. 4AtoFIG. 4C, a wavelength conversion module420A, a wavelength conversion module420B and a wavelength conversion module420C ofFIG. 4AtoFIG. 4Care respectively similar to the wavelength conversion module120, the wavelength conversion module320A and the wavelength conversion module320B ofFIG. 2A,FIG. 3AandFIG. 3B, and differences there between are as follows. As shown inFIG. 4AtoFIG. 4C, in the embodiment, the first standby region IB1of the wavelength conversion module420A, the wavelength conversion module420B, and the wavelength conversion module420C includes a first blank region BR1located between one of the at least one wavelength conversion region WR and one of the at least one non-conversion region NT adjacent thereto, and the second standby region IB2includes a second blank region BR2located between one of the at least one wavelength conversion region WR and one of the at least one non-conversion region NT adjacent thereto. In this way, when the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C is rotated, in the second time interval T2, a part of the at least one non-conversion region NT adjacent to the first blank region BR1, the first blank region BR1, and a part of the at least one wavelength conversion region WR adjacent to the first blank region BR1are sequentially cut into the transmission path of the first laser light beam50B formed during the turn-on time interval of the first laser light source110B (i.e. the first time interval T1or the third time interval T3). In the fourth time interval T4, a part of the at least one wavelength conversion region WR adjacent to the second blank region BR2, the second blank region BR2, and a part of the at least one non-conversion region NT adjacent to the second blank region BR2are sequentially cut into the transmission path of the first laser light beam50B formed during the turn-on time interval of the first laser light source110B (i.e. the first time interval T1or the third time interval T3).

In this way, since the first laser light source110B is turned off during the second time interval T2and the fourth time interval T4, no first laser light beam50B passes through the first standby region IB1or the second standby region IB2of the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C, and no light spot is formed on the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C by the first laser light beam50B, and therefore the phenomenon of image discoloration caused by the spoke state is not produced. Therefore, when the aforementioned illumination system100and projection apparatus200adopt any of the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C ofFIG. 4AtoFIG. 4C, the projection apparatus200does not need to turn off the light valve210in order to reduce the phenomenon of image discoloration during the operation of the light valve210, and therefore the brightness of the display image may be maintained.

In this way, in the embodiment, when any of the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C ofFIG. 4AtoFIG. 4Cis adopted, the illumination system100may also have the advantages of the aforementioned illumination system100and projection device200through configuration of the wavelength conversion module420A, the wavelength conversion module420B, or the wavelength conversion module420C, which is not repeated.

On the other hand, in the aforementioned embodiments, although the non-conversion region NT implemented by the light penetration region is taken as an example for description, the invention is not limited thereto. In other embodiments, the non-conversion region NT may also be a light reflection region. By referring to the invention, any person skilled in the art may make appropriate modifications to the design of the light paths of the illumination system100to achieve the similar effects and advantages as that of the aforementioned projection apparatus200, which is still considered to be within the scope of the invention. Some other embodiments are provided below for further description.

FIG. 5Ais a structural schematic diagram of another projection apparatus according to an embodiment of the invention.FIG. 5Bis a relationship diagram of transmittances of a second light splitting region of a first light splitting element ofFIG. 1to light of different wavebands. An illumination system300and a projection apparatus400ofFIG. 5Aare similar to the illumination system100and the projection apparatus200ofFIG. 1, and differences there between are as follows. Referring toFIG. 5A, the at least one non-conversion region NT of the wavelength conversion module120of the illumination system300is respectively formed by a reflective layer. Namely, in the embodiment, the at least one non-conversion region NT is a light reflection region, and is adapted to reflect the first laser light beam50B to form the first color light70B through the subsequent optical elements. To be specific, in the embodiment, a first light splitting element331of a light splitting and combining module330has a first light splitting region331aand a second light splitting region331b, and the light splitting and combining module330further includes a light converging lens333. In detail, in the embodiment, the first light splitting region331aof the first light splitting element331is disposed corresponding to the first laser light source110B, and is located between the first laser light source110B and the wavelength conversion module120, and the second light splitting region331bof the first light splitting element331is located on the transmission path of the first laser light beam50B reflected by the non-conversion region NT of the wavelength conversion module120, and the second light splitting region331bis located between the wavelength conversion module120and the second light splitting element132.

Further, in the embodiment, the first light splitting region331aof the first light splitting element331is, for example, a dichroic mirror with green reflection, and a relationship curve of transmittances of the first light splitting region331aof the first light splitting element331to light of different wavebands is the same as the relationship curve of the transmittances of the first light splitting element331to light of different wavebands shown inFIG. 2B, which is not repeated. Therefore, the first light splitting region331aof the first light splitting element331is pervious to blue light, and provides a reflection effect to green light. In this way, the first laser light beam50B of the first laser light source110B may still be transmitted to the wavelength conversion module120by penetrating through the first light splitting region331aof the first light splitting element331.

On the other hand, in the embodiment, the second light splitting region331bof the first light splitting element331is a dichroic mirror with green reflection and blue transflection. For example, as shown inFIG. 5B, the second light splitting region331bof the first light splitting element331may, for example, reflect light with a waveband within a range of 480 to 590 nm, and has a transmittance of 50% and a reflectance of 50% to light with a waveband below 480 nm, and is pervious to light with a waveband greater than 590 nm. In this way, as shown inFIG. 5A, when the first laser light beam50B is reflected to the second light splitting region331bby the non-conversion region NT of the wavelength conversion module120, a part of the first laser light beam50B is reflected to one side of the light converging lens333by the second light splitting region331bof the first light splitting element331, while the other part of the first laser light beam50B passes through the second light splitting region331bof the first light splitting element331and is transmitted to the second light splitting element132, and is then reflected to another side of the light converging lens333by the second light splitting element132. Moreover, the first laser light beam50B incident to the different sides of the light converging lens333may be combined by the light converging lens333to form the first color light70B.

On the other hand, the illumination system300may still respectively form the third color light70G and the second color light70R through the configuration of the wavelength conversion region WR of the wavelength conversion module120and the second laser light source110R. In the embodiment, light paths of the third color light70G and the second color light70R are the same as the light paths of the third color light70G and the second color light70R of the embodiment ofFIG. 1, and details thereof may be obtained by referring to the above paragraphs, which are not repeated.

In this way, the illumination system300and the projection apparatus400may produce the required color light in different time intervals through arrangement of the first laser light source110B, the second laser light source110R, and the wavelength conversion module120, and the phenomenon of image discoloration caused by the spoke state may be prevented, and the brightness of the display image is maintained. As such, the similar effects and advantages as that of the aforementioned illumination system100and the projection apparatus200are achieved, which are not repeated.

Moreover, as shown inFIG. 5A, in the embodiment, the illumination system300may also selectively include an optical uniforming unit OU, and the optical uniforming unit OU is located between the first light splitting element331and the light uniforming element140. In this way, in the illumination system300, the uniformity of the display image may be improved through arrangement of the optical uniforming unit OU.

FIG. 6Ais a structural schematic diagram of another projection apparatus according to an embodiment of the invention.FIG. 6Bis a relationship diagram of transmittances of a first light splitting element ofFIG. 6Ato light of different wavebands.FIG. 6Cis a relationship diagram of transmittances of a second light splitting element ofFIG. 6Ato light of different wavebands.FIG. 6Dis a relationship diagram of transmittances of a third light splitting element ofFIG. 6Ato light of different wavebands.FIG. 6Eis a timing schematic diagram of a first laser light source, a second laser light source, a third laser light source, a wavelength conversion module and a light valve ofFIG. 6Ain different time intervals. Referring toFIG. 6A, an illumination system500and a projection apparatus600of the embodiment ofFIG. 6Aare similar to the illumination system100and the projection apparatus200ofFIG. 1, and differences there between are as follows. As shown inFIG. 6AandFIG. 6E, in the embodiment, the illumination system500further includes a third laser light source110G. To be specific, the third laser light source110G is configured to provide a third laser light beam50G in a fifth time interval T5. For example, in the embodiment, the third laser light beam50G is a green laser light beam. For example, in the embodiment, the third laser light source110G may be one or a plurality of green laser diodes arranged in an array, but the invention is not limited thereto.

In detail, as shown inFIG. 6E, in the embodiment, the first laser light source110B is turned on during the first time interval T1and the third time interval T3and is turned off during the second time interval T2, the fourth time interval T4, and the fifth time interval T5. The second laser light source110R is turned on during the second time interval T2and the fourth time interval T4and is turned off during the first time interval T1, the third time interval T3, and the fifth time interval T5. The third laser light source110G is turned on during the fifth time interval T5and is turned off during the first time interval T1, the second time interval T2, the third time interval T3, and the fourth time interval T4. In other words, as shown inFIG. 6E, in the first time interval T1and the third time interval T3, only the first laser light beam50B is provided, in the second time interval T2and the fourth time interval T4, only the second laser light beam50R is provided, and in the fifth time interval T5, only the third laser light beam50G is provided.

On the other hand, in the embodiment, a light splitting and combining module530further includes a third light splitting element533, and the third light splitting element533is located between the second light splitting element532and the first light splitting element531, and is also located between the second light splitting element532and the third laser light source110G. Moreover, to be specific, in the embodiment, the first light splitting element531is, for example, a dichroic mirror with green-orange reflection, which is pervious to red and blue light, and provides a reflection effect to green-orange light. For example, as shown inFIG. 6B, in the embodiment, the first light splitting element531may, for example, reflect light with a waveband within a range of 480 to 590 nm, and is pervious to light with a waveband less than 480 nm or greater than 590 nm. The second light splitting element532is, for example, a dichroic mirror with cyan (i.e., a combination of blue and green) reflection, which is pervious to red light, and provides a reflection effect to blue light and green light. For example, as shown inFIG. 6C, in the embodiment, the second light splitting element532may reflect light with a waveband less than 600 nm, and is pervious to light with a waveband greater than 600 nm. The third light splitting element533is, for example, a dichroic mirror with blue and red reflection, which is pervious to green light, and provides a reflection effect to blue light and red light. As shown inFIG. 6D, in the embodiment, the third light splitting element533may, for example, reflect light with a waveband less than 470 nm or greater than 630, and is pervious to light with a waveband within a range of 470 nm to 630 nm.

Moreover, in the embodiment, the optical uniforming unit OU is located on transmission paths of the first laser light beam50B, the second laser light beam50R and the third laser light beam50G, and the wavelength conversion module120is also disposed on the transmission path of the third laser light beam50G.

In this way, as shown inFIG. 6AandFIG. 6E, in the first time interval T1, the non-conversion region NT of the wavelength conversion module120is cut into the transmission path of the first laser light beam50B, and the first laser light beam50B may penetrate through the non-conversion region NT of the wavelength conversion module120, and is sequentially transmitted to the second light splitting element532and the third light splitting element533through the light transmitting element LT, and is reflected to the first light splitting element531to form the first color light70B. In the third time interval T3, the wavelength conversion region WR of the wavelength conversion module120is cut into the transmission path of the first laser light beam50B, and the first laser light beam50B may be converted into the wavelength-converted light beam60Y of the yellow color by the wavelength conversion region WR of the wavelength conversion module120, and then the wavelength-converted light beam60Y is transmitted to the first light splitting element531, and is filtered by the first light splitting element531to form third color light70G1with a narrow spectrum range.

On the other hand, as shown inFIG. 6AandFIG. 6E, in the second time interval T2and the fourth time interval T4, since the second laser light source110R is turned on, the second laser light beam50R provided by the second laser light source110R may penetrate through the second light splitting element532, and is reflected to the first light splitting element531by the third light splitting element533to form the second color light70R. In the fifth time interval15, since the third laser light source110G is turned on, the third laser light beam50G provided by the third laser light source110G may penetrate through the third light splitting element533, and is reflected to the wavelength conversion module120by the second light splitting element532and the light transmitting element LT, and then the third laser light beam50G penetrates through the non-conversion region NT of the wavelength conversion module120and is transmitted to the first light splitting element531to form a fourth color light70G2.

Moreover, in the embodiment, the projection apparatus600and the illumination system500may adjust relative proportions of the first color light70B, the second color light70R, the third color light70G1and the fourth color light70G2of the illumination light beam70through time lengths of turn-on time intervals of the first laser light source110B, the second laser light source110R and the third laser light source110G and the configuration of the wavelength conversion region WR and the non-conversion region NT of the wavelength conversion module120. For example, in the embodiment, a ratio of a time length of the third time interval T3to a time length of the first time interval T1is between 0.5 and 1.5, a ratio of a time length of the second time interval T2or the fourth time interval T4to the time length of the first time interval T1is between 0.5 and 1.5, and a ratio of a time length of the fifth time interval15to the time length of the first time interval T1is between 1.5 and 3. In this way, in the illumination system500and the projection device600, a color temperature of the image light beam80may be adjusted without adjusting the intensity of the first laser light source110B or the second laser light source110R, thereby avoiding loss of the brightness of the display image.

Moreover, in the embodiment, since the fourth color light70G2in the illumination light beam70is green light with the narrow spectrum range, and the human eye is more sensitive to green light, when the purity or brightness of the green light is increased, the human eye may also feel a brighter brightness of the display image. In this way, through the configuration of the third laser light source110G and the first light splitting element531in the illumination system500and the projection apparatus600, the brightness of the display image perceived by human eyes is increased.

On the other hand, in the embodiment, the illumination system500and the projection apparatus600are capable of producing the required color light at different time intervals through arrangement of the first laser light source110B, the second laser light source110R, and the wavelength conversion module120, so that the phenomenon of image discoloration caused by the spoke state is prevented, and the brightness of the display image is maintained. Accordingly, the similar effects and advantages as that of the aforementioned illumination system100and projection apparatus200are achieved, which are not repeated.

FIG. 7Ais a structural schematic diagram of another projection apparatus according to an embodiment of the invention.FIG. 7Bis a top view of another wavelength conversion module ofFIG. 7A. Referring toFIG. 7A, an illumination system700and a projection apparatus800of the embodiment ofFIG. 7Aare similar to the illumination system500and the projection apparatus600ofFIG. 6, and differences there between are as follows. In the embodiment ofFIG. 6A, the wavelength conversion module120and the optical uniforming unit OU are respectively an independent single element. In the embodiment, as shown inFIG. 7AandFIG. 7B, the optical uniforming unit OU may be configured on a wavelength conversion module720to become a part of the wavelength conversion module720. To be specific, in the embodiment, the wavelength conversion module720includes a first annular region OR1and a second annular region OR2arranged in different radial ranges, where the two annular regions are, for example, concentric annular regions. For example, in the embodiment, an inner diameter of the second annular region OR2is greater than an inner diameter of the first annular region OR1, but the invention is not limited thereto. In other embodiments, the inner diameter of the second annular region OR2may be smaller than the inner diameter of the first annular region OR1.

To be more specific, as shown inFIG. 7B, a light diffusing element DF or/and a polarizing element PM of the optical uniforming unit OU is/are disposed on the first annular region OR1, and at least one wavelength conversion region WR and at least one non-conversion region NT of the wavelength conversion module720are disposed on the second annular region OR2. In this way, the first laser light beam50B may sequentially pass through the at least one non-conversion region NT located on the second annular region OR2and the optical uniforming unit OU located on the first annular region OR1to form the first color light70B. The second laser light beam50R may pass through the optical uniforming unit OU located on the first annular region OR1to form the second color light70R. The third laser light beam50G may sequentially pass through the optical uniforming unit OU located on the first annular region OR1and the at least one non-conversion region NT located on the second annular region OR2to form the fourth color light70G2.

In this way, the illumination system700and the projection apparatus800are also capable of producing the required color light at different time intervals through arrangement of the first laser light source110B, the second laser light source110R, the third laser light source110G, and the wavelength conversion module720, so that the phenomenon of image discoloration caused by the spoke state is prevented, and the brightness of the display image is maintained. Accordingly, the similar effects and advantages as that of the aforementioned illumination system500and projection apparatus600are achieved, which are not repeated.

In summary, the embodiments of the invention have at least one of following advantages or effects. In the embodiments of the invention, the illumination system and the projection apparatus are capable of producing the required color light at different time intervals through arrangement of the first laser light source, the second laser light source, and the wavelength conversion module, so that the phenomenon of image discoloration caused by the spoke state is prevented, and the brightness of the display image is maintained. Moreover, arrangement of a filter module in the projection apparatus and the illumination system may be omitted, so that the loss of brightness is reduced, and a 100% RGB color light output ratio (CLO) is achieved. Moreover, in the embodiments of the invention, the illumination system and the projection apparatus may adopt the illumination control method to simply switch the turn-on or turn-off state of the first laser light source and the second laser light source without limitation, so as to improve the color update rate of the projection apparatus and eliminate the color break issue to achieve smooth viewing quality.