Patent Description:
Head-up displays (HUDs) are widely applied to aircraft, vehicles, and retail store windows to show the information superimposed on the surrounding environment to the users. The vehicle may have a built-in head-up display device having a Picture Generation Unit (PGU) and an imaging module disposed therewithin. The information image generated by the PGU is projected outside to the windshield by the imaging module, such that the driver can see the driving information provided by the built-in head-up display device without having to look down at the dashboard or navigator while driving.

With the current technical architecture of the head-up display device, a single picture generation unit may only provide a single field of view (FOV) and generate a single virtual image, which limits the information that the head-up display device can display. Therefore, with the current technology, if a head-up display device is required to provide two fields of view and two virtual images at the same time, two sets of picture generation units must be used, which will increase the volume of the head-up display device. Moreover, since the head-up display device requires two sets of picture generation units, the number of elements required for the head-up display device and the production cost are increased.

The information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the Background section does not mean that one or more problems to be resolved by one or more embodiments of the disclosure was acknowledged by a person of ordinary skill in the art.

<CIT> and <CIT> both show an image generating unit according to the preamble of independent claim <NUM>.

It is an object of the present disclosure to provide an image generation unit and a head-up display, in which two imaging regions are simultaneously arranged with a single image generation unit and which at least reduces stray light and ghost images in the respective imaging regions.

Other objects and advantages of the disclosure can be further understood from the technical features disclosed in the disclosure.

The object is solved by the features of the independent claim.

In order to achieve one or part or all of the above purposes or other purposes, the disclosure provides an image generation unit, which includes: a display panel, a first illumination system, and a second illumination system.

The display panel has a first imaging region and a second imaging region which are adjacently arranged and located on a same plane. The first illumination system provides a first light beam which is incident on the first imaging region of the display panel at a first incident angle, and the first imaging region converts the first light beam into a first image beam. The second illumination system provides a second light beam which is incident on the second imaging region of the display panel at a second incident angle, and the second imaging region converts the second light beam into a second image beam. The optical path of the first light beam incident on the first imaging region does not intersect with the optical path of the second light beam incident on the second imaging region.

In one or more embodiments, the first image beam and the second image beam may leave the display panel at different light exit angles.

In one or more embodiments, the first incident angle and the second incident angle may be different.

In one or more embodiments, the first illumination system may comprise a first light source, a collimator and a light transmission assembly.

In one or more embodiments, the first light beam may be emitted from the first light source and may be guided by the collimator and the light transmission assembly in sequence, and then the first light beam may be incident on the first imaging region.

In one or more embodiments, the light transmission assembly of the first illumination system comprises a reflecting mirror.

In one or more embodiments, the reflecting mirror is disposed between the first illumination system and the second illumination system, such that an optical path of the first light beam incident on the first imaging region may not intersect with an optical path of the second light beam incident on the second imaging region. The reflecting mirror comprises a reflective surface to reflect the first light beam and a surface opposite to the reflective surface, wherein the opposite surface comprises a light absorbing element to absorb the second light beam incident on the reflecting mirror.

In one or more embodiments, the first light beam emitted by the first light source may be guided by the collimator and the light transmission assembly in sequence, and may be transmitted to the reflecting mirror.

In one or more embodiments, the first light beam may be reflected to the first imaging region by the reflecting mirror.

In one or more embodiments, the first light source may be one or more light-emitting elements.

In one or more embodiments, the light-emitting element may be a light-emitting diodes or a laser diode.

In one or more embodiments, the second illumination system may comprise a second light source, a collimator and a light transmission assembly.

In one or more embodiments, the second light beam may be emitted from the second light source and may be guided by the collimator and the light transmission assembly in sequence, and then the second light beam may be incident on the second imaging region.

In one or more embodiments, the second light source may be one or more light-emitting elements.

In one or more embodiments, the light-emitting element may be a light-emitting diode or a laser diode.

In one or more embodiments, the display panel may be a liquid crystal display panel.

In one or more embodiments, the image generation unit may further comprise a diffuser, disposed on the display panel.

In one or more embodiments, the diffuser may be located on the optical path where the first light beam is incident on the first imaging region and the optical path where the second light beam is incident on the second imaging region.

In one or more embodiments, the diffuser may be disposed on a light entrance surface of the display panel.

In one or more embodiments, the image generation unit may further comprise a first diffuser disposed on the first imaging region of the display panel.

In one or more embodiments, the image generation unit may further comprise a second diffuser disposed on the second imaging region of the display panel.

In one or more embodiments, the first diffuser and the second diffuser may have different diffusing abilities.

In one or more embodiments, the first light beam may be transmitted to the first imaging region after passing through the first diffuser and the second light beam may be transmitted to the second imaging region after passing through the second diffuser.

The disclosure also provides a head-up display, projecting a first image beam and a second image beam onto a target element, including: an image generation unit, and an image transmission module. The image generation unit includes: a display panel, a first illumination system, and a second illumination system. The display panel has a first imaging region and a second imaging region which are adjacently arranged and located on a same plane. The first illumination system provides a first light beam which is incident on the first imaging region of the display panel at a first incident angle, and the first imaging region converts the first light beam into the first image beam. The second illumination system provides a second light beam which is incident on the second imaging region of the display panel at a second incident angle, and the second imaging region converts the second light beam into the second image beam. An optical path of the first light beam incident on the first imaging region does not intersect with an optical path of the second light beam incident on the second imaging region, and the first image beam and the second image beam leave the display panel at different light exit angles. The image transmission module transmits the first image beam and the second image beam from the image generation unit to the target element so as to form a first virtual image and a second virtual image, respectively.

Based on the above, using this image generation unit architecture, through the design of the illumination system and the light transmission assembly, the function of providing illumination beams to two imaging regions simultaneously by one image generation unit can be achieved, and the two imaging regions have illumination systems that may both provide their respective imaging regions independently, such that the illumination systems of the two imaging regions can have better efficiency performance. Therefore, the overall architecture of the image generation unit and the head-up display has the advantages of smaller size, lower power consumption, lower cost, and the like.

In order to make the above-mentioned features and advantages of the disclosure more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

Other objectives, features and advantages of the disclosure will be further understood from the further technological features disclosed by the embodiments of the disclosure wherein there are shown and described exemplary embodiments of this disclosure, simply by way of illustration of modes best suited to carry out the disclosure.

The drawings illustrate embodiments and, together with the description, serve to explain the principles of the disclosure.

In the following detailed description of the exemplary embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. In this regard, directional terminology, such as "top," "bottom," "front," "back," etc., is used with reference to the orientation of the Figure(s) being described. The components of the disclosure can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the disclosure. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. Unless limited otherwise, the terms "connected," "coupled," and "mounted" and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms "facing," "faces" and variations thereof herein are used broadly and encompass direct and indirect facing, and "adjacent to" and variations thereof herein are used broadly and encompass directly and indirectly "adjacent to". Therefore, the description of "A" component facing "B" component herein may contain the situations that "A" component directly faces "B" component or one or more additional components are between "A" component and "B" component. Also, the description of "A" component "adjacent to" "B" component herein may contain the situations that "A" component is directly "adjacent to" "B" component or one or more additional components are between "A" component and "B" component. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

<FIG> is a schematic diagram of an image generation unit according to an embodiment of the disclosure. <FIG> is a schematic diagram of a head-up display according to an embodiment of the disclosure. Referring to <FIG> and <FIG>, an image generation unit <NUM> of a head-up display <NUM> provides a first image beam I1 and a second image beam I2, and the head-up display <NUM> projects the first image beam I1 and the second image beam I2 to a target element <NUM>. In this embodiment, the head-up display <NUM> is, for example, used in vehicles such as automobiles. For example, the head-up display <NUM> is installed under the dashboard of the vehicle. The target element <NUM> is, for example, a windshield of the vehicle. The first image beam I1 and the second image beam I2 are reflected by the target element <NUM> (the windshield) to eyes E of the viewer (for example, the driver of the vehicle), such that the viewer may see a first virtual image VM1 and a second virtual image VM2 that are formed at different imaging distances and show different driving information in front of the target element <NUM> (windshield).

<FIG> is a schematic diagram of an image generation unit according to an embodiment of the disclosure. As shown in <FIG>, the image generation unit <NUM> includes a display panel <NUM>, a first illumination system <NUM> and a second illumination system <NUM>. In the embodiment, the first illumination system <NUM> and the second illumination system <NUM> are arranged at the same side of the display panel. The display panel <NUM> includes a first imaging region <NUM> and a second imaging region <NUM> which are adjacently arranged to form an effective image region (not numbered) and corresponding to the first illumination system <NUM> and the second illumination system <NUM>, respectively. The first imaging region <NUM> and the second imaging region <NUM> are located on a same plane (the effective image region) of the display panel <NUM> so as to provide different, the same or related image information respectively. In the embodiment, the display panel <NUM> may include, for example, a transmissive liquid crystal panels or other light beam modulators.

As shown in <FIG>, the first illumination system <NUM> provides a first light beam L1, and the first imaging region <NUM> of the display panel <NUM> is located on the optical path of the first light beam L1. The first light beam L1 is incident on the first imaging region <NUM> of the display panel <NUM> at a first incident angle θ1i, and the first imaging region <NUM> of the display panel <NUM> converts the first light beam L1 into the first image beam I1. The second illumination system <NUM> provides a second light beam L2, and the second imaging region <NUM> of the display panel <NUM> is located on the optical path of the second light beam L2. The second light beam L2 is incident on the second imaging region <NUM> of the display panel <NUM> at a second incident angle θ2i, and the second imaging region <NUM> of the display panel <NUM> converts the second light beam L2 into the second image beam I2. Furthermore, the first incident angle θ1i is the included angle between a direction of the first light beam L1 and a normal N of the plane of the display panel <NUM>, and the second incident angle θ2i is the included angle between a direction of the second light beam L2 and the normal N of the plane of the display panel <NUM>.

As shown in <FIG>, the first illumination system <NUM> includes a first light source <NUM>, a collimator <NUM>, and a light transmission assembly <NUM>. The first light source <NUM> of the first illumination system <NUM> emits the first light beam L1. The first light beam L1 is guided by the collimator <NUM> and the light transmission assembly <NUM> in sequence to be incident on the first imaging region <NUM> of the display panel <NUM> by the collimator <NUM> and the light transmission assembly <NUM> in sequence.

According to some embodiments, the first light beam L1 may be monochromatic light or polychromatic light, but the disclosure is not limited thereto. According to some embodiments, the first light source <NUM> of the first illumination system <NUM> is one or more light emitting elements. The number of light-emitting elements may be determined according to requirements, which is not limited in the disclosure. According to some embodiments, the light-emitting element is a light-emitting diode or a laser diode, or other elements with similar properties; the disclosure is not limited thereto.

The collimator <NUM> of the first illumination system <NUM> is located on the optical path of the first light beam L1 emitted from the first light source <NUM> so as to collimate the first light beam L1. According to some embodiments, the divergence angle of the collimated first light beam L1 passing through the collimator <NUM> is smaller than <NUM>°, but it may be other suitable angles according to system requirements; the disclosure is not limited thereto.

As shown in <FIG>, the light transmission assembly <NUM> of the first illumination system <NUM> includes a lens <NUM>, a lens <NUM> and a reflecting mirror <NUM>. In this embodiment, the light transmission assembly <NUM> has two lenses and one reflecting mirror, but the number of lenses and reflecting mirrors may also be other suitable numbers according to system requirements; the disclosure is not limited thereto.

The first light beam L1 emitted by the first light source <NUM> passes through the collimator <NUM>, the lens <NUM> and the lens <NUM> in sequence, and is transmitted to the reflecting mirror <NUM>. Then the first light beam L1 is reflected by the reflecting mirror <NUM> to the first imaging region <NUM> of the display panel <NUM>. By adjusting the configuration of the first light source <NUM>, the collimator <NUM>, and the light transmission assembly <NUM>, especially the arrangement angle of the reflecting mirror <NUM>, the light entrance angle of the first light beam L1 incident on the first imaging region <NUM> may be adjusted to be the first incident angle θ1i. In this embodiment, the reflecting mirror <NUM> is a flat reflecting mirror. In other embodiments, the optical elements of the light transmission assembly <NUM> may also have other combinations and arrangements; the disclosure is not limited thereto.

As shown in <FIG>, the second illumination system <NUM> includes a second light source <NUM>, a collimator <NUM>, and a light transmission assembly <NUM>. The second light source <NUM> of the second illumination system <NUM> emits the second light beam L2. The light beam L2 is guided by the collimator <NUM> and the light transmission assembly <NUM> in sequence to be incident on the second imaging region <NUM> of the display panel <NUM>.

According to some embodiments, the second light beam L2 may be monochromatic light or polychromatic light; the disclosure is not limited thereto. According to some embodiments, the color of the second light beam L2 may be the same as the color of the first light beam L1, or may be different from the color of the first light beam L1; the disclosure is not limited thereto. According to some embodiments, the second light source <NUM> is one or more light emitting elements. The number of light-emitting elements may be determined according to requirements; the disclosure is not limited thereto. According to some embodiments, the number of light-emitting elements of the second light source <NUM> may be the same or different from the number of light-emitting elements of the first light source <NUM> the disclosure is not limited thereto. According to some embodiments, the light-emitting element is a light-emitting diode or a laser diode, or other elements with similar properties; the disclosure is not limited thereto.

The collimator <NUM> of the second illumination system <NUM> is located on the optical path of the second light beam L2 from the second light source <NUM> so as to collimate the second light beam L2. According to some embodiments, the divergence angle of the collimated second light beam L2 passing through the collimator <NUM> is smaller than <NUM>°, but it may be other suitable angles according to system requirements; the disclosure is not limited thereto.

As shown in <FIG>, the light transmission assembly <NUM> of the second illumination system <NUM> includes a lens <NUM>, a reflecting mirror <NUM>, and a lens <NUM>. In this embodiment, the light transmission assembly <NUM> has two lenses and one reflecting mirror, but the number of lenses and reflecting mirrors may also be other suitable numbers according to system requirements; the disclosure is not limited thereto.

The second light beam L2 emitted by the second light source <NUM> passes through the collimator <NUM> and the lens <NUM> in sequence, and is reflected by the reflecting mirror <NUM> to be transmitted to the lens <NUM>. The second light beam L2 passing through the lens <NUM> is incident on the second imaging region <NUM> of the display panel <NUM>. By adjusting the configuration of the second light source <NUM>, the collimator <NUM>, and the light transmission assembly <NUM>, the light entrance angle of the second light beam L2 incident on the second imaging region <NUM> may be adjusted to be the second incident angle θ2i. In other embodiments, the optical elements of the light transmission assembly <NUM> may also have other combinations and arrangements; the disclosure is not limited thereto.

The optical path of the first light beam L1 from the first light source <NUM> to be incident on the first imaging region <NUM> does not intersect with the optical path of the second light beam L2 from the second light source <NUM> to be incident on the second imaging region <NUM>, and the first image beam I1 and the second image beam I2 leave the display panel <NUM> at a first light exit angle θ1o and a second light exit angle θ2o, respectively. The first light exit angle θ1o and the second light exit angle θ2o are the included angles between the directions in which the first light beam L1 and the second light beam L2 leave the display panel <NUM> and the normal N of the plane of the display panel <NUM>.

Since the first incident angle θ1i of the first light beam L1 incident on the first imaging region <NUM> is different from the second incident angle θ2i of the second light beam L2 incident on the second imaging region <NUM>, the optical path of the first light beam L1 does not interfere with the second light beam L2, such that the first light beam L1 would not be incident on the second imaging region <NUM> and the second light beam L2 would not be incident on the first imaging region <NUM>. There are no unnecessary stray light and ghost images in subsequent images.

Therefore, as shown in <FIG>, the reflecting mirror <NUM> of the light transmission assembly <NUM> of the first illumination system <NUM> is disposed between the first illumination system <NUM> and the second illumination system <NUM>, such that the optical path of the first light beam L1 incident on the first imaging region <NUM> does not interfere with the optical path of the second light beam L2 incident on the second imaging region <NUM>. The reflecting mirror <NUM> is disposed between the two illumination systems, for example, by connecting with a casing (not shown) fixed to the head-up display. In more detail, the reflecting mirror <NUM> is, for example, disposed on one side of the display panel <NUM>, and may be inclined relative to the plane of the display panel <NUM> according to the actual optical path, such that the first light beam L1 is incident on the first imaging region <NUM> of the display panel <NUM> at the first incident angle θ1i. With the configuration of the reflecting mirror <NUM>, the interference between the optical paths of the first light beam L1 and the second light beam L2 the first imaging region <NUM> and the second imaging region <NUM> can be effectively blocked; at the same time, the configuration of the reflecting mirror of the first illumination system <NUM> is also provided, so as to meet the restriction of first incident angle θ1i of the first light beam L1 emitted by the first illumination system <NUM> required by the first imaging region <NUM>.

According to some embodiments, the reflective surface of the reflecting mirror <NUM> reflects the first light beam L1, and the other surface of the reflecting mirror <NUM>, that is, the opposite surface of the reflective surface of the reflecting mirror <NUM>, has a light absorbing element to absorb the second light beam L2 incident on the reflecting mirror, so as to prevent the stray light generated in the second illumination system <NUM> from entering the first illumination system <NUM> or entering the first imaging region <NUM> of the display panel <NUM>.

According to some embodiments, the display panel <NUM> is a liquid crystal display panel <NUM>, or other elements having similar functions. The first imaging region <NUM> and the second imaging region <NUM> of the display panel <NUM> provide different image information, for example, such that the first virtual image VM1 and the second virtual image VM2 respectively formed by the first image beam I1 and the second image beam I2 may present different driving information in front of the target element <NUM> (the windshield). According to some embodiments, the first virtual image VM1 formed by the first image beam I1 may show fixed driving information, such as vehicle speed, fuel level, mileage, and speed limit, and the second virtual image VM2 formed by the second image beam I2 may show driving information according to road conditions, such as left and right turn symbols, landmark information, warning symbols, or the like; the disclosure is not limited thereto.

The image generation unit <NUM> further includes a diffuser <NUM>, and the diffuser <NUM> is located on the optical path of the first light beam L1 incident on the first imaging region <NUM> and the optical path of the second light beam L2 incident on the second imaging region <NUM>. The diffuser <NUM> is disposed on the plane (a light entrance surface) of the display panel <NUM>. According to some embodiments, the image generation unit <NUM> may not need to include the diffuser <NUM>; the disclosure is not limited thereto.

As shown in <FIG>, the diffuser <NUM> includes a first diffuser <NUM> and a second diffuser <NUM>. The first diffuser <NUM> corresponds to the first imaging region <NUM> of the display panel <NUM> and is disposed on the first imaging region <NUM> of the display panel <NUM>, and the first light beam L1 is transmitted to the first imaging region <NUM> after passing through the first diffuser <NUM>. The second diffuser <NUM> corresponds to the second imaging region <NUM> of the display panel <NUM> and is disposed on the second imaging region <NUM> of the display panel <NUM>, and the second light beam L2 is transmitted to the second imaging region <NUM> after passing through the second diffuser <NUM>. With the first diffuser <NUM> and the second diffuser <NUM>, the uniformity and quality of the first light beam L1 passing through the first diffuser <NUM> and the second light beam L2 passing through the second diffuser <NUM> can be improved respectively. According to some embodiments, the first diffuser <NUM> and the second diffuser <NUM> have the same or different hazes so as to generate the same or different diffusing abilities according to actual requirements. Moreover, in other embodiments, the first diffuser <NUM> may be disposed between the first light source <NUM> and the first imaging region <NUM> of the display panel <NUM>, and the second diffuser <NUM> may be disposed between the second light source <NUM> and the display panel <NUM> of the second imaging region <NUM>.

According to the image generation unit <NUM> shown in <FIG>, with two illumination systems, two different image beams may be generated simultaneously from one single display panel <NUM> having two imaging regions, and the size of the image generation unit and reduce costs can be effectively reduced. Further, by the arrangement of the reflecting mirror <NUM>, the optical paths of the first light beam L1 and the second light beam L2 may be made non-intersecting, so as to avoid the interference between the first light beam L1 and the second light beam L2. In some embodiments, the number of illumination systems may be greater than two, and the number of imaging regions may be greater than two, so as to generate more virtual images.

<FIG> is a schematic diagram of a head-up display according to an embodiment of the disclosure. To simplify the drawing, the first image beam I1 and the second image beam I2 are only shown in the transmission direction along the optical axis.

As shown in <FIG>, the head-up display <NUM> includes the image generation unit <NUM>, an image transmission module <NUM> and the target element <NUM>. The first image beam I1 and the second image beam I2 emitted by the image generation unit <NUM> are projected onto the target element <NUM>. The first image beam I1 and the second image beam I2 are reflected by the target element <NUM> to the eyes E of the viewer, such that the viewer sees the first virtual image VM1 and the second virtual image VM2 that are formed at different imaging distances and show different image information in front of the target element <NUM>.

The image transmission module <NUM> of the head-up display <NUM> transmits the first image beam I1 and the second image beam I2 from the image generation unit <NUM> to the target element <NUM> so as to form the first virtual image VM1 and the second virtual image VM2 respectively.

As shown in <FIG> and <FIG>, the first image beam I1 and the second image beam I2 from the image generation unit <NUM> leave the display panel <NUM> of the image generation unit <NUM> at the first light exit angle θ1o and the second light exit angles θ2o that are different from each other, and are incident on the image transmission module <NUM>. As shown in <FIG>, the image transmission module <NUM> includes an imaging mirror set <NUM>, an imaging mirror set <NUM>, and a curved mirror <NUM>. The imaging mirror set <NUM> and the imaging mirror set <NUM> are respectively located on the optical paths of the first image beam I1 and the second image beam I2. The number and position of the lenses or mirrors of the image transmission module <NUM> may be adjusted according to requirements, and the disclosure is not limited thereto.

As shown in <FIG> and <FIG>, the imaging mirror set <NUM> has, for example, a reflecting mirror, and the imaging mirror set <NUM> has, for example, a reflecting mirror. The first image beam I1, after leaving the image generation unit <NUM>, is reflected by the reflecting mirror (the imaging mirror set <NUM>) and then is incident on the curved mirror <NUM>. The second image beam I2, after leaving the image generation unit <NUM>, is reflected by the reflecting mirror (the imaging mirror set <NUM>) and then is incident on the curved mirror <NUM>. Since the head-up display <NUM> is configured with only one display panel <NUM>, the first light beam L1 is incident on the first imaging region <NUM> at the first incident angle θ1i relative to the normal N of the display panel <NUM>, and the second light beam L2 is incident on and the second imaging region <NUM> at the second incident angle θ2i relative to the normal N of the display panel <NUM>. Further, the first image beam I1 and the second image beam I2 respectively leave at the first light exit angle θ1o and the second light exit angle θ2o relative to the normal N of the display panel <NUM>. Through the above angle design, the first image beam I1 and the second image beam I2 emitted from the same display panel <NUM> may be transmitted to the corresponding imaging mirror sets <NUM> and <NUM> respectively.

According to some embodiments, the curved mirror <NUM> may be a free-form mirror, but the disclosure is not limited thereto. The curved mirror <NUM> receives the first image beam I1 from the imaging mirror set <NUM> and the second image beam I2 from the imaging mirror set <NUM>. The first image beam I1 and the second image beam I2 are respectively transmitted to the target element <NUM> by the curved mirror <NUM> so as to correspondingly form the first virtual image VM1 and the second virtual image VM2. Because the transmission distances of the first image beam I1 and the second image beam I2 in the image transmission module <NUM> after being emitted from the display panel <NUM> are different, the first virtual image VM1 and the second virtual image VM2 have different imaging distances relative to the target element <NUM>. In more detail, by the image transmission module <NUM>, the optical path length of the first image beam I1 from the image generation unit <NUM> to the position of the first virtual image VM1 formed by the first image beam I1 is greater than the optical path length of the second image beam I2 from the image generation unit <NUM> to the position of the second virtual image VM2 formed by the second image beam I2. In other embodiments, the imaging mirror set <NUM> has, for example, a plurality of reflecting mirrors; the imaging mirror set <NUM> has, for example, a plurality of reflecting mirrors; and the number of reflecting mirrors of the imaging mirror set <NUM> and the imaging mirror set <NUM> may be different. As long as the transmission distances of the first image beam I1 and the second image beam I2 between the image transmission module <NUM> and the display panel <NUM> are different, the disclosure does not limit the number of reflecting mirrors.

<FIG> is a schematic diagram of a head-up display according to another embodiment of the disclosure. To simplify the drawing, the first image beam I1 and the second image beam I2 are only shown in the transmission direction along the optical axis. A head-up display <NUM> of <FIG> is similar to the head-up display <NUM> of <FIG>, and the main differences are as follows. In this embodiment, the head-up display <NUM> further includes an optical element <NUM> located between the image generation unit <NUM> and the imaging mirror set <NUM> and the imaging mirror set <NUM>.

When the optical path of the first image beam I1 and the second image beam I2 interfere with each other in the optical path of the head-up display, the eyes E of the users will see stray light. At the same time, the viewer may also see part of the second virtual image VM2 in the first virtual image VM1, or part of the first virtual image VM1 in the second virtual image VM2. In order to prevent the first image beam I1 from interfering with the second image beam I2 on the imaging system of the head-up display <NUM>, the first light beam L1 for generating the first image beam I1 and the second light beam L2 for generating the second image beam I2 are separated by the reflecting mirror <NUM>. Due to the structural design of the head-up display, the first image beam I1 leaving the image generation unit <NUM> may still interfere with the second image beam I2 leaving the image generation unit <NUM>. Therefore, the optical element <NUM> of the head-up display <NUM> is configured to separate the first image beam I1 and the second image beam I2, such that the first image beam I1 does not transmit to the imaging mirror set <NUM>, and the second image beam I2 does not transmit to the imaging mirror set <NUM>, so as to ensure that the first virtual image VM1 and the second virtual image VM2 do not have stray light interfering with each other and that the imaging quality is improved.

According to some embodiments, the material of the optical element <NUM> is a material having light absorbing properties. Moreover, the position or shape of the optical element <NUM> may be changed according to the design of the imaging system, so as to achieve the purpose of separating the first image beam I1 and the second image beam I2. The disclosure does not limit the position or shape of the optical element <NUM>.

According to other embodiments, the optical element <NUM> may also be a material having polarized light properties, such as a polarizer. As long as a polarized light transmission direction of the display panel (display panel <NUM> of <FIG>) and a polarized light transmission direction of the optical element <NUM> are perpendicular (ex. the included angle is <NUM> degrees), the effect of shielding the stray light of the first image beam I1 and the second image beam I2 can also be achieved. In this embodiment, the optical element <NUM> and the reflecting mirror <NUM> are respectively disposed on opposite sides of the display panel <NUM>, and may be disposed adjacent to the display panel <NUM>. In the embodiment of <FIG>, the reflecting mirror <NUM> is, for example, connected to the display panel <NUM> and is located between the two imaging regions, and the optical element <NUM> is disposed adjacent to the display panel <NUM>; the disclosure is not limited thereto as long as the design prevents the two light beams or the two image beams from interfering with each other.

To sum up, by the arrangement of two illumination systems, the image generation unit of the disclosure is capable of simultaneously providing illumination light beams to two imaging regions of one display panel. Therefore, the size and cost of the image generation unit can be effectively reduced, and the two virtual images displayed by the head-up display can have better imaging quality.

Claim 1:
An image generation unit (<NUM>), comprising: a display panel (<NUM>), a first illumination system (<NUM>), and a second illumination system (<NUM>), wherein
the display panel (<NUM>) has a first imaging region (<NUM>) and a second imaging region (<NUM>) which are adjacently arranged and located on a same plane thereof;
the first illumination system (<NUM>) provides a first light beam (L1) which is incident on the first imaging region (<NUM>) of the display panel (<NUM>) at a first incident angle (θ1i), and the first imaging region (<NUM>) converts the first light beam (L1) into a first image beam (I1); and
the second illumination system (<NUM>) provides a second light beam (L2) which is incident on the second imaging region (<NUM>) of the display panel (<NUM>) at a second incident angle (θ2i), and the second imaging region (<NUM>) converts the second light beam (L2) into a second image beam (I2),
wherein
a light transmission assembly (<NUM>) of the first illumination system (<NUM>) comprises a reflecting mirror (<NUM>), and the reflecting mirror (<NUM>) is disposed between the first illumination system (<NUM>) and the second illumination system (<NUM>), such that an optical path of the first light beam (L1) incident on the first imaging region (<NUM>) does not intersect with an optical path of the second light beam (L2) incident on the second imaging region (<NUM>), characterized in that the reflecting mirror (<NUM>) comprises a reflective surface to reflect the first light beam (L1) and a surface opposite to the reflective surface, wherein the opposite surface comprises a light absorbing element to absorb the second light beam (L2) incident on the reflecting mirror.