JP2007240864A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform display of both straight gaze and projection, to allow high luminance display and to miniaturize a display device. <P>SOLUTION: A laser device 101 is used for a light source 1, control parts 205, 206 which input drive current to the laser 101 corresponding to information are provided and a focal adjustment part 3 consisting of a variable focal lens is provided on an optical path of light emitted from the light 1. When the light source 1 is driven by current less than threshold current of laser oscillation, display is performed by directly displaying information light on a display surface and when the light source is driven by current equal to or more than the threshold current of laser oscillation to perform laser emission, display is performed by projecting the information light to the outside. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device that displays information such as an image using a laser device as a light source.

  As a conventional matrix display, that is, a display device in which pixels are arranged in a matrix, a display device using a matrix emission of a phosphor, for example, a CRT (cathode ray tube) or a plasma television, or a spatial light modulator such as a liquid crystal is used. Display devices such as liquid crystal televisions and liquid crystal projectors, and display devices using a self-luminous element matrix such as organic EL (Electro-Luminescence) displays and LED (light emitting diode) matrix displays have been proposed. In addition, a matrix display in which a laser element and a phosphor are combined has also been proposed (see, for example, Patent Document 1). In these display devices, large-scale equipment is required for production in accordance with the recent trend of upsizing. , Has become a big investment.

Therefore, a projection type (projection type) display has recently been attracting attention. Projection type displays are relatively small, manufacturing facilities are relatively simplified, and large screen displays are possible. In other words, this display method, which is made small and takes a large image, has the advantage that it requires relatively little investment, but it requires the preparation of a large display screen. .
Japanese Patent Application Laid-Open No. 07-20818

On the other hand, there are many small matrix displays on the market recently for image display of so-called mobile devices such as mobile phones and game machines, all of which are viewed on a larger screen and viewed by a large number of people. The current situation is that we cannot answer such requests.
On the other hand, as an image display device for both direct viewing and projection, by adopting a configuration in which a large projection lens can be supplementarily attached to the light emission side front surface of a small liquid crystal display of, for example, about 4 inches conventionally, For example, what projects an image etc. on a wall is known. However, in such a display device, there are disadvantages in that it is dark in luminance and that it is necessary to carry a large projection lens separately from the display device main body.

  In view of the above problems, an object of the present invention is to provide a display device capable of performing both direct view and projection display with high luminance, and to reduce the size of the display device.

In order to solve the above problems, a display device according to the present invention uses a laser device as a light source, includes a control unit that inputs a drive current to the laser device in accordance with information, and is on an optical path of light emitted from the light source. In addition, a focus adjustment unit including a variable focus lens is provided.
According to the present invention, in the above display device, when the light source is driven at a laser oscillation threshold current lower than that, the information light is directly displayed on the display surface of the display device, and the light source is driven at a laser oscillation threshold current or higher to obtain the laser. When light is emitted, the information light is projected and displayed outside.

As described above, in the display device of the present invention, a laser device is used as a light source, and a drive current is input to the laser device in accordance with information such as an image. In particular, the light emitted from the light source Since it is possible to adjust the focal length by providing at least a variable focus lens on the road, for example, an image or the like is displayed on both the display surface of the display device itself and a display surface such as an external screen or wall. It is possible to image light including information, that is, information light. Thereby, both direct view and projection display can be performed with high luminance, and such a display device can be realized with a small configuration.
In particular, when the light source is driven below the laser oscillation threshold current, the information light is directly displayed on the display surface of the display device. On the other hand, when the light source is driven above the laser oscillation threshold current to emit laser light, the information light is displayed. Can be displayed on a large screen by projecting the image onto an external screen or wall. In this case, since a laser device is used as the light source, sufficient luminance can be obtained both in the case of direct display and in the case of projection to the outside.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which can perform both a direct view and a projection display with high brightness | luminance is provided, and size reduction of a display apparatus can be achieved.

Examples of the best mode for carrying out the present invention will be described below, but the present invention is not limited to the following examples.
[1] First Embodiment A display device according to an embodiment of the present invention will be described with reference to FIG. Explanation will be made with reference to FIG.
As shown in FIG. 1, a display device 500 according to the present embodiment uses a laser device as the light source 1, in this case, for example, laser devices 101, 102, 103,. In this embodiment, the laser devices 101, 102, 103,... Are arranged in an array so that display is performed with one pixel as a pixel.
FIG. 2 is a schematic perspective configuration diagram of an example of the laser device 101. This laser device 101 shows a case where a general semiconductor laser array is used. A semiconductor layer such as a clad layer (not shown) including an active layer 12 made of a material corresponding to an oscillation wavelength is sequentially crystallized on a substrate 11. The laser elements 101a, 101b,... Are arrayed by etching processing that is formed by growth or the like and that divides each laser element. Further, although not shown, for example, the tops of the laser elements 101a, 101b,. The laser device 101 is configured by dividing and forming electrodes on the grooves or on the back side of the substrate 11. In the example shown in FIG. 2, the substrate 11 is shown as being submounted on a heat spreader 13 made of a material having good thermal conductivity and exhaust heat, such as SiC and AlN. The active layer 12 which is an optical region is typically shown. The dimensions and shape of such a laser device 101 vary depending on the material configuration, oscillation wavelength, and the like. For example, the thickness t1 of the substrate 11 is about 100 μm, the thickness t2 of the heat spreader 13 is about 100 μm, and the pitch P1 of the active layer 12 Can be formed with a resonator length Lr of about 400 μm. Note that the emitted light L of the semiconductor laser generally has a narrow light spread angle in a direction along the surface of the active layer 12 in the near-field pattern (this direction is referred to as a slow direction), and is relatively light in a direction perpendicular to this. Is wide (this direction is referred to as the fast direction), and the cross section of the light beam is almost elliptical.

Such a laser device 101 is formed on a wafer 10 made of Si or the like as shown in the schematic plan view of FIG. In the case of a general 3-inch wafer, for example, there are 180 elements of 50 mm to 300 μm in the side A1 corresponding to the extending direction (pitch direction) of the laser array from within the rectangular region A having one side A1 and the other side A2. About 100 elements of 50 mm to 500 μm are formed in the side A2 corresponding to the cavity length direction of the laser elements, and a total of about 18000 elements are formed. Even if the yield is about 60%, it can be said that about 10,000 wafers can be produced from one wafer. For example, such laser elements may be cut in an array and arranged in parallel on the heat spreader 13 described above, or each laser element may be taken out independently and arranged in a two-dimensional matrix.
FIG. 4 shows a schematic perspective view of the state in which the laser elements are arranged in a matrix. In this case, an example is shown in which laser devices 101, 102, 103,... In which laser elements are arranged in an array are arranged in parallel and laser elements are arranged in a two-dimensional matrix.
As described above, since the total thickness including the heat spreader 13 can be about 200 μm, for example, the pitch P2 can be set to 300 μm.

FIG. 5 is a schematic perspective view showing a state in which the laser device 101, 102, 103,... Shown in FIG. 4 is connected to the wiring 51 formed on a separate substrate (not shown) at the mount portion 5. 4 and 5, parts corresponding to those in FIG. The wiring 51 is connected to an external drive current applying unit (not shown).
As shown in FIG. 5, in this example, each laser element is connected in the vertical direction, that is, in a direction intersecting with the arrangement direction of the laser devices 101, 102, 103,. In this case, the laser light is extracted to the side opposite to the mount portion 5, that is, the front side of each semiconductor laser element shown in FIG. By using a light-transmitting substrate and a light-transmitting conductive layer as the substrate and wiring material for forming the wiring 51, the leaked light can be observed on the back surface during laser oscillation, and it can also be seen directly. It is. In addition, although not shown, for example, by arranging a light output sensor on the back surface and taking out a signal from a wiring extending in the vertical direction in the same manner, it is also possible to monitor the light emission amount of each laser element.

  On the other hand, as shown in FIG. 1, for example, light emitted from the laser devices 101, 102, 103,. A lens 2 in which cylindrical lenses 201, 202, 203,... For shaping a light beam are arranged in parallel is provided, and a focus adjusting unit in which variable focus lenses 301, 302, and 303 are arranged in a matrix in front of the lens 2 3 is provided.

An arrangement example of the lens 2 and the focus adjusting unit 3 is shown in a schematic perspective view of FIG. In the illustrated example, the variable focus lens 301 of the focus adjusting unit 3 is positioned on the light emission side of the lens 2 including the cylindrical lenses 201, 202, 203,... At a position corresponding to the light emitting region of a laser element (not shown). , 302, 303,... Are arranged.
In the example shown in FIG. 6, the light output sensor 4 that detects the output of light emitted from the laser devices 101, 102, 103,... Shown in FIG. , 203,... Shows a case where the output sensor 4 is provided corresponding to the light emitting region of each laser element. The light output sensor 4 is configured by arranging light receiving elements such as photodiodes in a matrix on a light transmissive substrate, and includes light emitting end faces of the laser devices 101, 102, 103,... Shown in FIG. An example in which the lens 2 is arranged at a position shifted from the optical axis of the lens 2 on the optical path between the lens 2 and the light incident surface is shown. With such a configuration, the light output sensor 4 detects the leakage light of the light emitted from the laser devices 101, 102, 103,..., For example, the output from each light sensor 4 in the vertical direction. By connecting to the extended wiring 41, the optical output of the laser element in the vertical direction can be detected as shown in FIG.

Next, the variable focus lens will be described.
7A and 7B are views for explaining the principle of a general variable focus lens using a conductive liquid. As shown in FIG. 7A, an insulating layer 32 made of a dielectric film or the like and a water repellent coat 33 are formed on the electrode 31, and a conductive liquid 34, for example, a water droplet, is placed on the insulating layer 32 and contacted therewith. Let the angle be θ ₀ . As shown in FIG. 7B, when the voltage V is applied between the electrode 31 and the conductive liquid 34 by the voltage application unit 35, the contact angle θ ₁ of the conductive liquid 34 changes to θ _{1 such} that θ ₁ <θ _0. To do. Such a surface change of the conductive liquid 34 is represented by the following formula (1).
γ _LG × (cos θ ₁ −cos θ ₀ ) = {(ε ₀ × ε) / 2e} × V ² (1)
However,
γ _LG : Surface energy of conductive liquid
θ ₀ : Contact angle when a non-voltage is applied to the conductive liquid
θ ₁ : Contact angle at the time of voltage application of conductive liquid
ε: dielectric constant of the insulating layer
ε ₀ : dielectric constant in vacuum
e: film thickness of the insulating layer
V: Applied voltage.

By utilizing such characteristics, for example, a conductive liquid and an insulating liquid are contained in a cylindrical container, and the interface shape of the conductive liquid and the insulating liquid is changed by applying a voltage, thereby making it possible to change the variable focus lens. Can be configured. Such a varifocal lens does not require a driving unit such as a motor, which is advantageous for downsizing and thinning of a device to be used. In addition, a variable focus type microlens array can be configured by arranging in an array or matrix.
FIG. 8 shows a schematic perspective configuration diagram of an example of the focus adjustment unit 3 in which variable focus lenses are arranged in such a matrix. In this example, a partition wall 37 made of Si or the like is formed on a substrate 36A made of a light transmissive material such as glass, and an electrode and an insulating layer (not shown) are formed in a region partitioned by the partition wall 37 into, for example, a planar circular shape. The conductive liquid 34 is applied with the surface curve shown in FIG. 7A. The insulating liquid 38 is injected thereon, and the other substrate 36B made of glass or the like is deposited along the edge of the substrate 36A through a spacer 39 made of, for example, an insulating material to form the focus adjusting unit 3. Is done. In this case, the individual areas separated by the partition walls 37 are the variable focus lenses 301, 302,. Although not shown, the electrode structure includes, for example, an electrode layer and a dielectric layer made of a light-transmitting conductive material between the substrate 36A and the conductive liquid 34 and between the partition wall 37 and the conductive liquid 34 and the insulating liquid 38. It is constructed by stacking. You may apply | coat a water-repellent coat partially as needed. By applying an appropriate voltage between these electrodes, the interface shape of the conductive liquid 34 and the insulating liquid 38 of the variable focus lenses 301, 302,. It is possible to adjust the focus of the light passing through. In addition, it is good also as a structure which applies a uniform voltage to each variable focus lens 301,302, ..., and adjusts a focus uniformly. Moreover, the wiring structure of a matrix form etc. is provided and it applies for every variable focus lens. It is also possible to adjust the focal length by adjusting the voltage to be adjusted.

  Next, in the display device 500 having such a configuration, a driving mode in which the laser devices 101, 102,... Are driven to display information such as images will be described. As described above, when a semiconductor laser element is used, the emitted laser light has different divergence angles between the fast direction and the slow direction. However, the lens 2 including the cylindrical lenses 201, 202, 203,. Is converged to the same degree as the divergence angle in the slow direction. Thereafter, the light enters each variable focus lens 301, 302, 303,... Of the focus adjustment unit 3 that can be adjusted electrically. A predetermined potential is supplied to the varifocal lenses 301, 302, 303,..., And the divergence angle can be adjusted in accordance with the projection distance by making the light from the light source 1 substantially parallel.

In this display device, when a relatively low current less than the laser oscillation threshold current is applied to the laser device, each laser element emits LED light, so that it can be directly viewed through the display surface. When a relatively high current exceeding the laser oscillation threshold current is applied, the projection screen is displayed by adjusting the focus adjustment unit 3 to increase the focal length and projecting the laser beam on an external screen or wall. It becomes possible to do. In this case, an infrared sensor or the like may be provided in the projection area, and a safety mechanism such as stopping light emission when a human body approaches the display surface of the display device may be provided.
In addition, as described above, the wiring 51 is made of a light-transmitting conductive material, and the wiring 51 is formed on the light-transmitting substrate, so that it is possible to display by direct view with the leaked light from the back side.
Note that a monochromatic display device can be configured by using, for example, only a red (wavelength: about 643 nm) semiconductor laser as the laser device of the light source. When combined with a blue or green semiconductor laser, it is also possible to form a full-color image display device with the same configuration, with about three times the number of pixels.

  In addition, it is necessary to emit information with the left and right reversed on the display screen provided in the display device main body and on the display screen when projected to the outside. For this reason, for example, as shown in FIG. 1, an information signal such as a video signal is output from the information signal storage unit 21 to the arithmetic circuit 24 via the inversion processing unit 23. In the inversion processing unit 23, the information signal is inverted left and right as necessary based on the signal from the switching unit 22 and output to the arithmetic circuit 24.

  That is, when displaying information on the display surface of the display device body, the switching signal from the switching unit 22 is turned off, for example, the inversion processing in the inversion processing unit 23 is not performed, and the information signal such as video is controlled from the arithmetic circuit 24. Part, that is, the row signal control unit 25 and the column signal control unit 26. Each of the control units 25 and 26 outputs signals Sc1, Sc2, Sc3,..., Sr1, Sr2, Sr3,. Is driven. At this time, a current less than the threshold current is supplied to the laser devices 101, 102,... Further, in the focus adjustment unit 3 including the variable focus lenses 301, 302,..., Information light such as an image is emitted to the display surface of the display device by adjusting the focal length relatively short. In this case, the display is directly viewable.

  On the other hand, when displaying information on an external display surface, the switching signal from the switching unit 22 is turned on, for example, and the inversion processing unit 23 inverts and outputs the information. Then, for example, signals corresponding to video information are output from the arithmetic circuit 24 to the row signal control unit 25 and the column signal control unit 26, respectively, and the row signal control unit 25 and the column signal control unit 26 respectively correspond to appropriate drive currents. Signals Sc1, Sc2, Sc3,..., Sr1, Sr2, Sr3,... Are output to a drive voltage power source (not shown) to drive each laser device. In this case, a current equal to or higher than the threshold current is supplied to the laser devices 101, 102,..., And laser light by laser oscillation is emitted. In the focus adjustment unit 3 including the variable focus lenses 301, 302,..., The laser light is imaged on the display surface outside the display device by adjusting the focal length relatively long, and for example, an image corresponding to the information is displayed. Displayed on the external display screen. The focal lengths of the variable focus lenses 301, 302,... Of the focus adjustment unit 3 are controlled by using the signals output from the switching unit 22 described above, and the variable focus lenses 301, 302,. It is good also as a structure input into the control part etc. of these common electrodes.

  Further, in this example, an example is shown in which the light emitted from the laser device is detected by the light output sensor 4 and converted into an electrical signal and output to the light output sensor signal detector 27. Here, the uniformity (uniformity) of the display screen is confirmed in advance at the time of inspection at the time of shipment, for example, and the drive value of each pixel, that is, each laser device is determined as a calibration value. This calibration value is used as the luminance correction data. This is stored in the storage unit 28. When displaying an image, the light output sensor 4 detects and feeds back the light emitted from the laser device and compares the detected value with the drive value. If the detected value is different from the calibration value, the laser By determining that the element has deteriorated and making corrections, for example, by increasing the drive current, it is possible to suppress variations in the brightness of the emitted light. In the case of using a semiconductor laser, the deterioration characteristics of each laser element constituting the pixel are different. Therefore, it is possible to maintain the uniformity of the display screen, that is, uniformity, by correcting the output reduction due to this deterioration.

  According to the display device according to the embodiment of the present invention described above, a laser device is used as a light source and a focus adjustment unit including a variable focus lens is provided. Therefore, by adjusting the drive current, direct viewing and projection can be performed. Both displays can be performed, high-luminance display is possible, and no projection lens is required, so that the display device can be downsized.

Next, in the display device having the configuration of the present invention including the light source, the focus adjustment unit, and the like described with reference to FIGS.
[2] Second Embodiment FIG. 9 shows a light source matrix having about 12 × 5 pixels in the display device 500 according to the embodiment of the present invention described with reference to FIGS. An example applied to a display device capable of performing, for example, a digital clock display is shown. 9A is a plan configuration diagram of the display surface 500S of the display device 500, and FIG. 9B is a schematic configuration diagram when projecting from the display device 500 onto a display surface 501 such as an external screen.
When displaying on the display surface 500S of the display device 500 as shown in FIG. 9A, the switching signal from the switching unit 22 is turned off, for example, as in the example described in FIG. The laser device is caused to emit LED light with a drive current less than the threshold current of the laser device. In this case, the focal length adjustment unit 3 including the variable focus lenses 301, 302,... Selects a relatively short focal length, and performs direct view type display on the display surface 500S of the display device 500. On the other hand, as shown in FIG. 9B, when projecting on a display surface 501 such as an external screen or wall, a switching signal is output from the switching unit 22 and displayed on the display surface 500 </ b> S of the display device 500 in the inversion processing unit 23. The output information signal is reversed left and right and output, and laser light is emitted from the light source 1 with a drive current equal to or greater than the threshold current of the laser device, and the focal length of the focus adjustment unit 3 including the variable focus lenses 301, 302,. Is adjusted so that the information light Lp forms an image on the external display surface 501, and the information light is emitted. By performing such control, it is possible to switch between display on the display surface 500S of the main body of the display device 500 and display on the external display surface 501. In this case, since the laser device is used as the light source, the luminance can be sufficiently maintained when displaying on either display surface. Further, since a separate projection lens is not required, the apparatus can be miniaturized.

  In this example, since the total number of pixels is relatively small, such as about 60, for example, it can be manufactured by arranging laser pointers or the like. However, as in the display device of the present invention, the laser device is arranged in a matrix. Further downsizing can be achieved by arranging and configuring in the above. When forming a 12 × 5 light source matrix, for example, if laser elements made of semiconductor lasers are arranged at a pitch of 300 μm, the size becomes 3.6 mm × 1.5 mm. When the laser elements are arranged at intervals of 3 mm, the size is 36 mm × 15 mm, and a display device such as a wristwatch can be configured. Since it is sufficient that the output of each laser element is 1 mW, it is not necessary to provide a special cooling mechanism, and the configuration for measures against heat can be simplified.

[2] Third Embodiment FIG. 10 shows a display device according to an embodiment of the present invention described with reference to FIGS. 1 to 8 described above, and a QVGA (Quarter Video Graphics Array: pixel) of about 4 inches. A number 320 × 240) type display device 510, for example, an example applied to a portable game machine is shown. FIG. 10A is a plan configuration diagram of the display surface 510S of the display device 510, and FIG. 9B is a schematic configuration diagram when projecting from the display device 510 onto a display surface 511 such as an external screen.
Also in this case, as shown in FIG. 10A, the threshold value of the laser device is used when displaying on the display surface 510S of the display device 510 main body from the switching unit 22 in FIG. The laser device is caused to emit light with a driving current less than the current. Then, the focal length adjustment unit 3 including the variable focus lenses 301, 302,... Selects a relatively short focal length, and performs direct view type display on the display surface 510S of the display device 510. On the other hand, as shown in FIG. 10B, when projecting on a display surface 511 such as an external screen or wall, a switching signal is output from the switching unit 22 described in FIG. The displayed information signal is inverted left and right to be output, and the laser light is emitted from the light source 1 with a drive current equal to or higher than the threshold current of the laser device, and the focus of the focus adjustment unit 3 including the variable focus lenses 301, 302,. The information light Lp is emitted by adjusting the distance and adjusting the information light to form an image on the external display surface 511. By performing such control, display on the display surface 510S of the main body of the display device 510 and display on the external display surface 511 can be performed. Also in this case, since the laser device is used as the light source, the luminance can be sufficiently maintained in any display surface. Further, since a separate projection lens is not required, the apparatus can be miniaturized.

  In this example, since the number of pixels is about 320 × 240 to 76800, as described above, when using a semiconductor laser, about eight wafers are required, but the number of laser elements used for the light source is different. Only, it is the same as the example demonstrated in the above-mentioned FIGS. As an example, when the interval between the laser elements arranged in the light source is set to 300 μm pitch, the display device can be configured with a practical size of about 96 mm × 72 mm, which is 300 μm × 320 to 96 mm and 300 μm × 240 to 72 mm. It can be said that it is possible. For mounting such a number of laser elements, a conventionally known LED matrix display mounting method is applied, LDs are arranged instead of LEDs, and the variable focus lens having the configuration shown in FIG. 8 is arranged. By disposing the focused lens adjustment unit in front of the exit surface of the LD, it can be easily manufactured.

[4] Fourth Embodiment FIG. 11 shows a display device according to an embodiment of the present invention described with reference to FIG. 1 to FIG. An example applied to. FIG. 11A is a plan configuration diagram of the display surface 520S of the display device 520, and FIG. 11B is a schematic configuration diagram when projecting from the display device 520 to the display surface 521 such as an external screen.
Also in this case, as shown in FIG. 11A, in the case of displaying on the display surface 520S of the display device 520 main body from the switching unit 22 in FIG. The laser device is caused to emit light with a drive current less than the threshold current of the device. Then, the focal length adjustment unit 3 including the variable focus lenses 301, 302,... Selects a relatively short focal length, and performs direct-view display on the display surface 520S of the display device 520. On the other hand, as shown in FIG. 11B, when projecting on a display surface 521 such as an external screen or wall, a switching signal is output from the switching unit 22 described in FIG. The displayed information signal is inverted left and right to be output, and the laser light is emitted from the light source 1 with a drive current equal to or higher than the threshold current of the laser device, and the focus of the focus adjustment unit 3 including the variable focus lenses 301, 302,. The distance is adjusted so that the information light is focused on the external display surface 521, and the information light Lp is emitted. By performing such control, display on the display surface 520S of the main body of the display device 520 and display on the external display surface 521 can be performed. Also in this case, since the laser device is used as the light source, the luminance can be sufficiently maintained in any display surface. Further, since a separate projection lens is not required, the apparatus can be miniaturized.

  In this case, a so-called tiling configuration in which the QVGA type display device 510 described in the above third embodiment is bonded can also be used. For example, in the case of an XGA (eXtended Graphics Array: 1024 × 768) type display device, when laser elements are similarly arranged at a pitch of 300 μm, they become 300 μm × 1024 to 307 mm, 300 μm × 768 to 230 mm, and the diagonal 383. A display device 520 having a size of about 6 mm to 15.1 inches can be formed.

[5] Fifth Embodiment FIG. 12 shows a display apparatus according to an embodiment of the present invention described with reference to FIGS. ). 12A is a plan configuration diagram of the display surface 530S of the display device 530, and FIG. 12B is a schematic configuration diagram when projecting from the display device 530 to the display surface 531 such as an external screen.
Also in this case, as shown in FIG. 12A, in the case of displaying on the display surface 530S of the display device 530 main body from the switching unit 22 in FIG. The laser device is caused to emit light with a drive current less than the threshold current of the device. Then, the focal length adjustment unit 3 including the variable focus lenses 301, 302,... Selects a relatively short focal length, and performs direct-view display on the display surface 530S of the display device 530. On the other hand, as shown in FIG. 12B, in the case of projecting on a display surface 521 such as an external screen or wall, a switching signal is output from the switching unit 22 described in FIG. The displayed information signal is inverted left and right to be output, and the laser light is emitted from the light source 1 with a drive current equal to or higher than the threshold current of the laser device, and the focus of the focus adjustment unit 3 including the variable focus lenses 301, 302,. The distance is adjusted so that the information light is focused on the external display surface 521, and the information light Lp is emitted. By performing such control, display on the display surface 530S of the main body of the display device 530 and display on the external display surface 531 can be performed. Also in this case, since the laser device is used as the light source, the luminance can be sufficiently maintained in any display surface. Further, since a separate projection lens is not required, the apparatus can be miniaturized.
In this example, similarly to the above-described third embodiment, when the laser elements of the laser device are arranged at a pitch of 300 μm, they are 300 μm × 1920 to 676 mm, 300 μm × 1080 to 324 mm, and a diagonal of 749.6 mm to A display device 530 having a size of about 29.5 inches can be formed.

[6] Sixth Embodiment FIG. 13 shows an example in which the display device according to the embodiment of the present invention described with reference to FIGS. 1 to 8 is applied to a display device such as a traffic light. 13A is a plan configuration diagram of the display surface 540S of the display device 540, and FIG. 12B is a schematic configuration diagram when projecting from the display device 540 to the external display surfaces 542 and 543, respectively.
In this case as well, as shown in FIG. 13A, in the case of displaying on the display surface 540S of the display device 540 main body from the switching unit 22 in FIG. The laser device is caused to emit light with a drive current less than the threshold current of the device. Then, the focal length adjustment unit 3 including the variable focus lenses 301, 302,... Selects a relatively short focal length, and performs direct-view display on the display surface 540S of the display device 540. On the other hand, as shown in FIG. 13B, in the case of projecting on a display surface 542 or 543 such as an external screen or wall, a switching signal is output from the switching unit 22 described in FIG. The information signal displayed on 530 is reversed left and right and output, and the laser light is emitted from the light source 1 with a drive current equal to or higher than the threshold current of the laser device, and the focus adjustment unit 3 including variable focus lenses 301, 302,. Is adjusted so that the information light forms an image on the external display surface 542 or 543, and the information light is emitted. At this time, by providing the drive unit 541 in the display device 540, for example, the display device 540 is rotated as indicated by an arrow a to displace the emission direction of the display device 540, and information light is transmitted to the display surfaces 542 and 543 at different positions. It is possible to project Lp1 and Lp2. By performing such control, display on the display surface 540S of the main body of the display device 540 and display on the external display surfaces 542 and 543 can be performed. Also in this case, since the laser device is used as the light source, the luminance can be sufficiently maintained in any display surface. Further, since a separate projection lens is not required, the apparatus can be miniaturized.
In this case, it is also possible to adopt a configuration in which information light is projected onto two or more external display surfaces without providing a display surface in the display device 540 main body.
By applying such a display device as a traffic light, the display surfaces 542 and 543 provided at a high position are provided with only a diffusion plate that is easy to maintain, and replacement and cleaning of components such as a light source and a wiring section are performed at a low position. The main body of the display device 540 that requires maintenance such as work can be installed, and the maintenance can be simplified.

  As described above, in the display device of the present invention, the laser device is used as the light source, and the control unit that inputs the drive current to the laser device corresponding to the information is provided, and on the optical path of the light emitted from the light source. In addition, by disposing a focus adjustment unit including a variable focus lens, it is possible to provide both a direct view and a projection display with high luminance, and to provide a display device that can be miniaturized. That is, in the display device of the present invention, a separate projection lens is not required by disposing an electrically adjustable variable focus lens corresponding to the laser element constituting each pixel, for example, 4 inches. A display device that is small and easy to carry can be realized.

Also, when adjusting the drive current and driving the light source below the laser oscillation threshold current, displaying the information light directly on the display surface of the display device and driving the light source above the laser oscillation threshold current to cause laser emission Can be easily switched between a direct-view image in the LED mode and a projection mode in the laser oscillation mode by projecting information light to the outside, and can easily realize direct-view and projection Have
Moreover, in the case of applying to a large display device, it has a display screen of about 32 inches as a permanent type, and when you want to see it on a large screen of about 100 inches, for example, by projecting it on the opposite wall, Display on a large screen can be realized easily.

Further, in the display device of the present invention, when information light is projected to the outside by laser light emission from the light source, information such as characters, images, and images is provided by providing an inversion processing unit that projects the information light by reversing left and right. Can be easily displayed as a direct view type and a projector type.
Furthermore, in the display device of the present invention, by providing a light output sensor that detects the output of light emitted from the light source, the variation in luminance due to deterioration of characteristics such as a change in the light source over time is corrected, and the display screen is longer. It is possible to maintain uniformity, that is, uniformity.
Further, in the display device of the present invention, by providing a driving unit that displaces the direction in which the information light is emitted, projection display on two or more external display surfaces provided at different positions is possible.

  Note that the display device according to the present invention is not limited to the above-described embodiments, and uses a light source in which laser elements are arranged in an array without using an array laser as a light source, a lens, a focus adjustment unit, and the like. Needless to say, the shape and matrix arrangement of the optical component can be changed, and various modifications and changes can be made without departing from the configuration of the present invention.

1 is a schematic configuration diagram of a display device according to an exemplary embodiment of the present invention. It is a schematic perspective view of an example of the laser apparatus used for the display apparatus which concerns on the example of embodiment of this invention. It is a schematic plan view of a semiconductor wafer. It is a schematic perspective view of an example of the light source used for the display apparatus which concerns on the example of embodiment of this invention. It is a schematic perspective view of the principal part of the display apparatus which concerns on the example of embodiment of this invention. It is a schematic perspective view of the principal part of the display apparatus which concerns on the example of embodiment of this invention. A and B are explanatory views of the principle of the variable focus lens. It is a schematic perspective view of an example of the focus adjustment part used for the display apparatus which concerns on the example of embodiment of this invention. A is a schematic plan view of a display device according to an embodiment of the present invention. B is a schematic configuration diagram illustrating a display mode of a display device according to an exemplary embodiment of the present invention. A is a schematic plan view of a display device according to an embodiment of the present invention. B is a schematic configuration diagram illustrating a display mode of a display device according to an exemplary embodiment of the present invention. A is a schematic plan view of a display device according to an embodiment of the present invention. B is a schematic configuration diagram illustrating a display mode of a display device according to an exemplary embodiment of the present invention. A is a schematic plan view of a display device according to an embodiment of the present invention. B is a schematic configuration diagram illustrating a display mode of a display device according to an exemplary embodiment of the present invention. A is a schematic plan view of a display device according to an embodiment of the present invention. B is a schematic configuration diagram illustrating a display mode of a display device according to an exemplary embodiment of the present invention.

  1. 1. light source; Lens, 3. 3. Focus adjustment unit 4. light output sensor; 10. mount part; Substrate, 12. Active layer, 13. Heat spreader, 21. Information signal storage unit, 22. Switching unit, 23. Inversion processing unit, 24. Arithmetic circuit, 25. Low signal control unit, 26. Column signal controller, 27. Light output sensor signal detection section, 28. Brightness correction data storage unit 31. Electrodes, 32. Insulating layer, 33. Water repellent coat, 34. Conductive liquid, 35. Voltage application section, 36A. Substrate, 36B. Substrate, 37. Partition, 38. Insulating liquid, 39. Spacers, 41. Wiring, 51. Wiring 101-103. Laser device 201-203. Cylindrical lens, 301-303. Variable focus lens, 500. Display device, 500S. Display surface 501. Screen, 540. Drive part

Claims (5)

A laser device is used as the light source,
A control unit for inputting a drive current to the laser device corresponding to the information;
A display device comprising: a focus adjusting unit including a variable focus lens on an optical path of light emitted from the light source. When the light source is driven below the laser oscillation threshold current, information light is directly displayed on the display surface of the display device,
The display device according to claim 1, wherein when the light source is driven at a laser oscillation threshold current or more to emit laser light, information light is projected to the outside and displayed. The display device according to claim 2, further comprising: an inversion processing unit configured to project the information light by reversing left and right when the information light is projected to the outside by causing the light source to emit laser light. The display device according to claim 1, further comprising a light output sensor that detects an output of light emitted from the light source. The display device according to claim 1, wherein the display device is provided with a drive unit that displaces a direction in which the information light is emitted.

Images