JP2015063223A - Vehicle display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle display device capable of highly accurately performing automatic focusing with a simple configuration.SOLUTION: A stripe image J is displayed on a light intensity detection section 270. Light intensity is detected by the light intensity detection section 270 while moving the stripe image J. Transition data of an output signal Q of the light intensity detection section 270 associated with moving amount P is acquired. A difference between a maximum output Qmax and a minimum output Qmin is determined in the transition data of the output signal Q. The position (a back focus BF) of projection means 240 is adjusted so that the difference between the maximum output Qmax and the minimum output Qmin may be maximum.

Description

  The present invention relates to a vehicle display device that displays a virtual image.

  A head-up display device, which is a display device for vehicles, is mainly composed of a display device including a light source unit and a display element (liquid crystal display panel, etc.), a reflective mirror such as a concave mirror, an exterior housing, and a dustproof cover. ing. The display light from the display is reflected by a reflecting mirror such as a concave mirror and enters a reflecting means such as a windshield through a dustproof cover installed in the opening. The incident light is reflected by a reflecting means such as a windshield, so that video information is presented as a virtual image formed in front of the windshield or the like.

  The head-up display device disclosed in Patent Document 1 includes a light source unit, a display, and a lens as a projection unit, and image information generated by the light source unit and the display is transferred onto an imaging member of the light guide by the lens. This is a structure for projecting and forming a real image. As the light source unit, for example, various lamps such as halogen lamps, LEDs, scanner type projectors, and the like are used. For the display, a display element such as a liquid crystal display panel or DMD is used. By adopting such a configuration, it is possible to provide a head-up display device in which the degree of freedom in designing the size, shape, arrangement, and the like is higher than in the past.

JP 2004-126226 A

However, in the head-up display device disclosed in Patent Document 1, the dimensions and optical physical properties of the projection means change due to changes in the temperature of the environment and changes in the characteristics of the component parts over time. The real image of is blurred.
The present invention has been made in view of this problem, and provides a display device for a vehicle that can be automatically focused with high accuracy with a simple configuration.

  The present invention includes a light source that emits illumination light, a reflective display element that spatially modulates the illumination light and reflects it as display light, a projection unit that projects the display light reflected by the reflective display element, An image forming member that forms an image of the display light projected by the projection unit on a display surface; and a light intensity detection unit that detects a light intensity of the display light from the projection unit. A focus adjustment unit that displays a test image alternately having different luminance areas on the light intensity detection unit while moving the image, and corrects the position of the projection unit according to an output signal of the light intensity detection unit; , With.

  The focus adjustment unit corrects the position of the projection unit so that the difference between the maximum value and the minimum value of the output signal of the light intensity detection unit is maximized.

  Provided is a display device for a vehicle which can be automatically focused with a simple configuration and high accuracy.

1 is a schematic sectional view showing an embodiment of the present invention. The figure which shows the structure of the indicator of embodiment same as the above. The front view and sectional drawing of the transmissive screen of embodiment same as the above. The block diagram which shows embodiment same as the above. It is a figure explaining the mode of the movement of the stripe image of embodiment same as the above. It is a figure which shows the transition data of the output signal of embodiment same as the above. It is a flowchart of the focus adjustment process of embodiment same as the above.

  Hereinafter, an embodiment in which a vehicle display device of the present invention is applied to a head-up display device (hereinafter referred to as a HUD device) 100 will be described with reference to the accompanying drawings.

  The HUD device 100 is mounted on, for example, an automobile. As shown in FIG. 1 and the like, the housing 10, the display 20, the plane mirror 30, the concave mirror 40, the actuator 50, and a control board (not shown) The display light L representing the display image M displayed by the display device 20 is reflected by the plane mirror 30 and the concave mirror 40 and irradiated to the windshield 200 of the vehicle on which the HUD device 100 is mounted for display. . The contents displayed by the HUD device 100 in this way are various vehicle information, navigation information, and the like.

The housing 10 is composed of an upper case 11 and a lower case 12 made of, for example, black light-shielding synthetic resin. By engaging the upper case 11 and the lower case 12, a plane mirror 30, a concave mirror 40, The actuator 50 is housed inside, and the display device 20 and the control board are attached to the outside.
The upper case 11 has an opening 11a that allows display light L to be described later to pass through the windshield 200 at a portion facing the windshield 200, and the opening 11a is covered with a translucent cover 11b. Further, the upper case 11 has a light shielding wall 11c at a location near the plane mirror 30 of the opening 11a, and external light incident from the opening 11a (the translucent cover 11b) is directed to the plane mirror 30 side or the display 20 side. Prevent progress.
The lower case 12 includes a plane mirror 30, a concave mirror 40, an actuator 50, and an indicator 20 attached to the outside, and an engaging portion (not shown) for engaging a control board, respectively, 20, the plane mirror 30, the concave mirror 40, the actuator 50, the control board, etc. are each positioned and fixed. The lower case 12 has a display port 12 a that is opened so that the display image M displayed by the display device 20 faces the plane mirror 30. Although not shown, the lower case 12 also has a wiring hole through which wiring for supplying various signals and power from the control board to the actuator 50 and the display 20 is inserted.

The display 20 displays the display image M on a transmission screen 260 described later, and the detailed configuration will be described in detail.
The plane mirror 30 is formed by forming a reflective film on the surface of a base material made of, for example, a synthetic resin material by means such as vapor deposition, and directs the display light L of the display image M emitted from the display device 20 toward the concave mirror 40. It is to be reflected.

  The concave mirror 40 is formed by forming a reflective film on the surface of a base material made of, for example, a synthetic resin material by means such as vapor deposition. The concave mirror 40 further reflects the display light L reflected by the plane mirror 30 and emits it toward the windshield 200. To do. The display light L reflected by the concave mirror 40 passes through the translucent cover 11 b provided in the opening 11 a of the housing 10 and travels toward the windshield 200. The display light L that reaches and is reflected on the windshield 200 forms a virtual image (display image visually recognized by the observer E) V of the display image M at a position in front of the windshield 200. As a result, the HUD device 100 allows the observer E (mainly the driver of the vehicle) to visually recognize both the virtual image V and the outside scene that actually exists in front of the windshield 200. In addition, the concave mirror 40 has a function as a magnifying glass, and magnifies the display image M displayed on the display device 20 and reflects it to the windshield 200 side. That is, the virtual image V visually recognized by the observer E is an enlarged image of the display image M displayed by the display device 20.

  The actuator 50 includes a motor (not shown), a power transmission member (not shown) such as a gear that transmits the power of the motor to the concave mirror 40, and a support base (not shown) that supports the motor, the power transmission member, and the concave mirror 40. And the concave mirror 40 is rotated around the rotation axis AX. The motor generates power for rotating the concave mirror 40 around the rotation axis AX, and includes, for example, a stepping motor. The motor rotates the motor in response to an electric signal and power supply from the control unit 300, which will be described later, and the power transmission member transmits power to the concave mirror 40 to rotate the concave mirror 40 around the rotation axis AX. Below, the specific structure of the indicator 20 is demonstrated using FIG.

  As shown in FIG. 2, the display 20 is reflected by the light output unit 210 that emits the illumination light C, the reflection mirrors 221 and 222 that guide the illumination light C to the reflective display element 230, and the reflection mirrors 221 and 222. In order to receive the illumination light C and generate a desired display image M, the illumination light C is spatially modulated and reflected as image light K in the direction of the projection means 240, and the reflection display element 230 The image light K is incident, the image light K is adjusted in the direction of divergence and enlarged and projected onto the transmission screen 260, the moving mechanism 250 for moving the projection means 240, and the image from the projection means 240. A transmissive screen 260 that receives the light K on the back surface and displays the display image M on the front surface, and a light intensity detector 270 that is disposed in the vicinity of the transmissive screen 260 and detects the light intensity are provided.

  The light output unit 210 includes a red light source 211R, a green light source 211G, a blue light source 211B, a dichroic mirror 212R, and a dichroic mirror 212G, and emits red, green, and blue light beams emitted from the red light source 211R, the green light source 211G, and the blue light source 211B. The light is emitted as illumination light C with the optical axes aligned in substantially the same direction.

  The red light source 211R, the green light source 211G, and the blue light source 211B are, for example, LEDs, and emit red, green, and blue light beams, respectively, by supplying power from a control board (not shown). In particular, when the light source is an LED, it is necessary to control the input power to be low in order to reduce damage to the element at a high temperature, and there is a thermistor in the vicinity of the red light source 211R, green light source 211G, and blue light source 211B. Temperature detection means is provided to detect the temperature of the LED section. Further, in order to suppress the red light source 211R, the green light source 211G, and the blue light source 211B from becoming high temperature, the heat sink 20a (see FIG. 1) is used to radiate the heat of the red light source 211R, the green light source 211G, and the blue light source 211B to the outside. )It is connected to the.

  The dichroic mirror 212R is a glass substrate that is coated with a thin film that reflects light emitted from the red light source 211R and transmits light emitted from the green light source 211G and the blue light source 211B. The dichroic mirror 212G is formed by coating a glass substrate with a thin film having a characteristic of reflecting the light emitted from the green light source 211G and transmitting the light emitted from the blue light source 211B.

  The optical axes of the light beams of the respective light sources are aligned in substantially the same direction via the dichroic mirror 212R and the dichroic mirror 212G.

  The reflection mirrors 221 and 222 are formed by coating a glass substrate with a thin film having a characteristic of reflecting light emitted from the red light source 211R, the green light source 211G, and the blue light source 211B. Light is incident on the reflective display element 230 at an appropriate angle by reflection.

  The reflective display element 230 is, for example, a DMD (Digital Micromirror Device) that is a light modulation element. The reflective display element 230 employs a field sequential display method in which incident red light, green light, and blue light are modulated according to a red video signal, a green video signal, and a blue video signal, respectively. As a result, red, green, and blue images are sequentially displayed and synthesized by the human eye and recognized as a color image. Further, since the DMD is easily damaged by temperature and it is necessary to control the ON / OFF period and the intensity of the light source while monitoring the element temperature, the temperature detecting means 231 is incorporated.

  The temperature detection unit 231 is built in the reflective display element 230 in the present embodiment, but may be disposed in the projection unit 240. The temperature detection means 231 incorporated in the reflective display element 230 and the temperature detection means (for example, thermistor) provided on the circuit board (not shown) on which the red light source 211R, the green light source 211G, and the blue light source 211B are mounted Since it can be said that the temperature detection means is necessary for reducing damage due to the temperature of the reflective display element 230 and the light source, if the temperature of the projection means 240 is detected using these, it is possible to omit the additional temperature detection means. .

  The projecting means 240 is a group of a plurality of lens groups arranged in a cylindrical exterior called a lens barrel, and has a function of making the image light K generated by the reflective display element 230 incident and adjusting the focus. The projected image is enlarged and projected onto the transmission screen 260.

The moving mechanism 250 moves the projection unit 240 in the normal direction of the transmissive screen 260 based on a drive signal from the control unit 300 described later, and forms the display image M just on the surface of the transmissive screen 260.

The transmission screen 260 receives the image light K from the projection unit 240 on the back surface and transmits the image light K, thereby displaying the display image M on the front surface side. For example, a holographic diffuser, a microlens array, a diffusion plate, etc. Consists of. Further, as shown in FIG. 3, the transmissive screen 260 includes a screen holding portion 261 formed of a resin material or the like around the display area 260 a for displaying the display image M, and is provided at a predetermined position of the screen holding portion 261. A plurality of light intensity detection holes 261a facing each of a plurality of light intensity detection units 270 (271, 272, 273, 274) described later are provided.

The light intensity detection unit 270 is a sensor that detects light intensity, such as a photodiode or a color sensor, and is disposed in the light intensity detection hole 261 a of the transmission screen 260. In the present embodiment, a light intensity detector 271 (below the display area 260a in FIG. 3), a light intensity detector 272 (above the display area 260a in FIG. 3), at the outer center of the four sides of the display area 260a, A light intensity detector 273 (on the right side of the display area 260a in FIG. 3) and a light intensity detector 274 (on the left side of the display area 260a in FIG. 3) are provided.

  The HUD device 100 changes the size and optical physical properties of the projection means 240 due to changes in temperature, changes with time, etc., and changes the positional relationship of each optical element due to vehicle vibrations. Although there is a problem that the real image is blurred, the present invention is provided with a focus adjustment unit that adjusts the position of the projection unit 240 so as to obtain an appropriate back focus BF that hardly causes display blur.

  As shown in FIG. 4, the electrical configuration of the focus adjusting means includes a light source 211 that emits illumination light C, a reflective display element 230 that modulates illumination light C into image light K, and focuses image light K. The projection unit 240 for adjustment, a moving mechanism 250 for moving the projection unit 240, a light intensity detection unit 270 for detecting the light intensity, and a control unit 300 to be described later are mainly configured and displayed on the transmission screen 260. The focus of the display image M to be adjusted is adjusted.

  The projection means 240 has a joint nut fixing part 240a and a guide insertion part 240b (see FIG. 2). The joint nut fixing portion 240 a is a power transmission portion to which the joint nut 252 is fixed and moves the projection means 240 as the joint nut 252 moves. The guide insertion part 240b is a part through which the guide 253 for guiding the movement of the projection unit 240 is inserted. The guide insertion portion 240b and the guide 253 are provided with a clearance so that movement in an unintended direction is restricted and movement in the intended direction is smooth.

  The power transmission means 251 is made of, for example, a well-known PM type stepping motor that generates a rotational driving force by energization, and the rotating shaft extending from the power transmission means 251 is a screw formed in a spiral shape on the peripheral surface thereof. The lead screw 251a is a groove. The arrangement is such that the axial direction of the lead screw 251a is parallel to the direction of the back focus BF to be adjusted.

  The joint nut 252 is provided with a hole that meshes with the thread groove of the lead screw 251a, and a shape fixed to the joint nut fixing portion 240a of the projection means 240 is provided on the side surface. When the lead screw 251a is rotated by driving the power transmission means 251, the joint nut 252 engaged with the thread groove of the lead screw 251a moves linearly along the axial direction of the lead screw 251a. The projection means 240 fixed via the fixing part 240a also moves linearly.

  The guide 253 extends in a direction parallel to the direction of the back focus BF to be adjusted, is inserted through the guide insertion portion 240b of the projection unit 240, and functions to prevent the projection unit 240 from moving in an unintended direction. The spring 254 is inserted into the guide 253, and a force acts so as to stretch the guide insertion portion 240b of the projection unit 240. There is play (so-called backlash) between the thread groove of the lead screw 251a and the joint nut 252 meshing therewith, but the spring 254 functions to hold down the play.

  The stopper 255 is provided on the linear movement path of the joint nut fixing portion 240a of the projection means 240. By driving the power transmission means 251, the joint nut fixing portion 240a can move until it abuts against the stopper 255. This abutted position is set as an absolute reference position for setting an appropriate position according to the temperature of the projection means 240.

  The control unit 300 includes a microcontroller, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and the like, and includes an input processing unit 301, a memory control unit 302, a buffer 303, a memory 304, and a drawing control unit. 305 and an arithmetic processing unit 306, which are electrically connected to the light source 211, the reflective display element 230, the temperature detecting means 231, the moving mechanism 250, the light intensity detecting unit 270, the actuator 50, etc. A display image M based on the image data is generated on the transmissive screen 260 by controlling the light source 211 and the reflective display element 230 based on image data input from an ECU (not shown).

  The input processing unit 301 inputs an image signal from the ECU on the vehicle side, performs processing such as gamma correction and distortion correction on the data, and puts the data into a format suitable for processing in the control unit 300.

  The memory control unit 302 stores the image data converted by the input processing unit 301 in the buffer 303. The buffer 303 includes a volatile memory such as a DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory), a rewritable nonvolatile memory such as a flash memory, or the like. When the memory control unit 302 stores the image data input from the vehicle side in the buffer 303, the memory control unit 302 reads the test image data stored in advance from the memory 304 included in the control unit 300, and the image input from the vehicle side. The test image data is combined with the data and stored in the buffer 303.

  The memory control unit 302 takes out image data (including test image data) from the buffer 303 and outputs it to the drawing control unit 305 upon receiving a command from the drawing control unit 305 to be described later. The data is stored in a memory (not shown) in the drawing control unit 305.

  The drawing control unit 305 executes the program data stored in advance to output drive signals to the light source 211 and the reflective display element 230, thereby controlling the light source 211 and the reflective display element 230 to transmit light. A display image M based on the image data and a stripe image (test image) J having a vertical stripe pattern based on the test image data are generated on the screen 260. Specifically, the drawing control unit 305 displays the display image M in the display area 260a on the transmissive screen 260, and stripe images on the light intensity detection unit 270 provided in the screen holding unit 261 outside the display area 260a. J is displayed.

  As shown in FIG. 3, the stripe image J is composed of a white display high luminance area Ja and a black display low luminance area Jb. In the memory 304 of the stripe image J, the horizontal widths (widths in the horizontal direction in FIG. 3) Da and Db of the high luminance area Ja and the low luminance area Jb are respectively the light of the screen holding unit 261 in which the light intensity detection unit 270 is disposed. The intensity detection hole 261a is stored in advance as test image data so as to be substantially the same as the lateral width (width in the horizontal direction in FIG. 3) H. A vertical stripe image J is displayed on the light intensity detectors 271 and 272 arranged in the vertical direction of the display image M, and the light intensity detectors 273 and 273 arranged in the horizontal direction of the display image M are displayed. On 274, a horizontal stripe image J is displayed.

  In the present embodiment, since the display format is a field sequential display method, the red light source 211R, the green light source 211G, and the blue light source 211B are sequentially turned on at high speed in white in the high brightness area Ja of the stripe image J, and these are combined. The white color is expressed. Therefore, the light intensity detector 270 sequentially outputs output signals of red, green, and blue light intensities to the control unit 300 (arithmetic processor 306). The arithmetic processor 306 detects the light intensity. The output signals of the red, green, and blue light intensities input from the unit 270 are integrated for a certain period (for example, one frame period), and this integrated value is used as the output signal Q of the light intensity detection unit 270 to generate the stripe image J. In association with the movement amount P, it is stored in a storage area (not shown) of the arithmetic processing unit 306. In this way, as shown in FIG. 5, the arithmetic processing unit 306 moves the stripe image J by a predetermined slide movement amount P, and outputs the output signal Q of the light intensity detection unit 270 and the movement amount P of the stripe image J. Are associated and stored in the storage area, as shown in FIG. 6, output signal transition data (N 0, N 0, association between the output signal Q of the light intensity detector 270 and the movement amount P of the stripe image J). N1, N2, etc.).

  The arithmetic processing unit 306 calculates the focus parameter Fi for determining the focus state from the difference between the maximum output Qmax and the minimum output Qmin of the acquired output signal transition data (Fi = Qmax−Qmin). When the focus is on the transmissive screen 260, the boundary between the high brightness area Ja and the low brightness area Jb of the stripe image J is clear, and therefore the difference (focus parameter Fi) between the maximum output Qmax and the minimum output Qmin is large. When the maximum is reached (output signal transition data N2 in FIG. 6) and the focus is not achieved on the transmissive screen 260, the boundary between the high brightness area Ja and the low brightness area Jb of the stripe image J is unclear. The difference (focus parameter Fi) between Qmax and the minimum output Qmin becomes small (output signal transition data N0 and N1 in FIG. 6). The focus adjustment processing operation will be described below with reference to FIG.

(Focus adjustment processing)
First, in step S <b> 1, the control unit 300 displays the stripe image J on the light intensity detection unit 270. The light intensity detector 270 detects the light intensity of the light emitted to the light intensity detection hole 261 a and outputs a signal to the control unit 300. In step S2, as described above, the arithmetic processing unit 306 integrates the output signals of the red, green, and blue light intensities input from the light intensity detecting unit 270 for a certain period, and this integrated value is integrated with the light intensity detecting unit. The output signal Q of 270 is stored in the storage area of the arithmetic processing unit 306 in association with the movement amount P of the stripe image J. In step S3, the control unit 300 determines whether the moving amount P of the stripe image J has moved by a predetermined amount. If the moving amount P has not moved by the predetermined amount (No in step S3), the control unit 300 moves the stripe image J by a certain amount (sliding movement). After moving the amount p), the process proceeds to step S2, and steps S2 and S3 are repeated until the moving amount P of the stripe image J moves by a predetermined amount (until step S3 becomes Yes).

  When the moving amount P of the stripe image J has moved by a predetermined amount (when Step S3 becomes Yes), the storage area is associated with the moving amount P as shown in FIG. 6 when graphed. The transition data of the output signal Q (for example, output signal transition data N0) is stored. In step S4, the arithmetic processing unit 306 calculates a focus parameter F0 that is the difference between the maximum output Qmax and the minimum output Qmin of the output signal transition data N0, and temporarily stores the calculated focus parameter F0 in the storage area in step S5. Hold on.

  In step S6, the control unit 300 compares the latest focus parameter Fi with the focus parameter F (i-1) calculated before that. If Fi <F (i-1) is not satisfied (No in step S6), the projection unit 240 is moved via the moving mechanism 250 to adjust the back focus BF. Then, the control unit 300 returns the movement amount P to the initial value, returns to step S2, and again transition data of the output signal Q until the movement amount P moves by a predetermined amount (for example, the output signal transition in FIG. 6). Data N1) is stored, and the focus parameter F1 is held in the storage area.

  If Fi <F (i−1) in step S6 (Yes in step S6), the control unit 300 compares the second calculated focus parameter F1 with the first calculated focus parameter F0, and F1 < It is determined whether it is F0 (step S7). If F1 <F0 (Yes in step S7), the control unit 300 determines that the adjustment direction of the back focus BF is moving in a direction in which the display image M is out of focus, and the adjustment direction of the back focus BF. And the second focus parameter F1 is recalculated by starting over from step S2. With such a configuration, even when the adjustment direction of the back focus BF is moved in a direction in which the display image M is out of focus, the adjustment direction of the back focus BF is automatically corrected to a direction in which the display image M is in focus. Can do.

  If the result of step S7 is No, the control unit 300 indicates that the back focus BF at the focus parameter F (i-1) calculated immediately before is the focus of the display image M on the surface of the transmissive screen 260. The focus parameter F (i-1) is stored in the storage area as the maximum focus parameter Fa (step S8). Next, the control unit 300 adjusts the back focus BF by moving the projection unit 240 via the moving mechanism 250 so that the back focus BF is obtained when the maximum focus parameter Fa is detected.

  In the present invention, as described above, the stripe image J is displayed on the light intensity detection unit 270, the light intensity is detected by the light intensity detection unit 270 while the stripe image J is moved, and is associated with the movement amount P. The obtained transition data of the output signal Q of the light intensity detector 270 is obtained, the difference between the maximum output Qmax and the minimum output Qmin in the transition data of the output signal Q is obtained, and the difference between the maximum output Qmax and the minimum output Qmin By adjusting the position (back focus BF) of the projection means 240 so that the maximum is displayed, the display image M displayed on the transmissive screen 260 with a simple configuration without using a complicated configuration such as an imaging means. The focus can be adjusted.

  In addition, this invention is not limited by the said embodiment and drawing. Of course, changes (including deletion of components) can be added to these.

  In the above description, the optimum back focus BF is determined based on the output signal Q of one light intensity detection unit 270, but the present invention is not limited to this. The back focus BF is set to a predetermined value, and the light intensity detector 271 disposed below the display area 260a shown in FIG. 3 and the light intensity detection disposed above the display area 260a shown in FIG. A stripe image J is displayed on both the unit 272 and the focus parameter Fi calculated from the light intensity detected by the light intensity detection unit 271 and the focus calculated from the light intensity detected by the light intensity detection unit 272 The back focus BF that maximizes the sum with the parameter Fi may be the optimal back focus BF. In this way, the focus parameter Fi (maximum output Qmax) calculated from the detection signals of a plurality (two) of light intensity detectors 270 disposed at positions with the center of the display image M (display region 260a) as a symmetric point. By adjusting the focus based on the sum of the difference between the minimum output Qmin and the minimum output Qmin, the display image M between the plurality (two) of light intensity detectors 270 can be accurately focused.

  In the above description, the focus parameter Fi is the difference between the maximum output Qmax and the minimum output Qmin of the output signal Q associated with the movement amount P. However, the present invention is not limited to this, and light intensity detection per unit time is detected. The average value or integral value of the output signal of the unit 270 may be used. Further, the focus parameter Fi may be calculated by Fi = (maximum output Qmax−minimum output Qmin) / (maximum output Qmax + minimum output Qmin) so as to calculate the ratio between the maximum output Qmax and the minimum output Qmin.

  In the above description, the high brightness area Ja is white. However, the present invention is not limited to this, and the high brightness area Ja may be a single color such as red, green, and blue. Alternatively, the light intensity detection unit 270 may output only the light intensity of one of the colors as the output signal Q to the control unit 300 while displaying the high luminance area Ja in white.

Further, the focus adjustment process may be performed continuously or intermittently while the display image M is displayed, and the temperature detected by the temperature detecting means 231 changes by a predetermined value or more after a predetermined time has elapsed. In such a case, focus adjustment processing may be performed. Further, the back focus BF may be changed when the focus parameter Fi calculated continuously or intermittently is separated from the maximum focus parameter Fa stored in the storage area by a predetermined value. With such a configuration, it is possible to prevent the display state of the display image M from being frequently changed due to frequent adjustment of the back focus BF.
Further, the drive direction of the moving mechanism 250 (adjustment direction of the back focus BF) at the time of performing the focus adjustment processing may be switched according to the temperature change direction (temperature rise or temperature drop) of the temperature detection unit 231. .

DESCRIPTION OF SYMBOLS 100 HUD apparatus (display apparatus for vehicles), 10 housing | casing, 20 indicator, 210 light output part, 221 and 222 reflection mirror, 230 reflection type display element, 231 temperature detection means, 240 projection means, 250 moving mechanism, 260 transmission Screen, 270 (271-274) Light intensity detection unit, 30 plane mirror, 40 concave mirror, 50 actuator, C illumination light, AX rotation axis, BF back focus, E observer, J stripe image, K image light, L display light, M display image, S optical path, V virtual image, 200 windshield, 300 control unit, 301 input processing unit, 302 memory control unit, 303 buffer, 304 memory, 305 drawing control unit, 306 arithmetic processing unit, Ja high brightness area, Jb Low brightness area, Fi focus parameter, Q Force signal, Qmax maximum output, Qmin minimum output, P moving amount, 270 (271 to 274) the light intensity detector

Claims (2)

  A light source that emits illumination light, a reflective display element that spatially modulates the illumination light and reflects it as display light, a projection means that magnifies and projects the display light reflected by the reflective display element, and the projection means An image forming member that forms an image of the display light that is enlarged and projected on a display surface, and a light intensity detection unit that detects the light intensity of the display light from the projection unit, and the reflective display element includes: A focus adjustment unit that displays a test image alternately having different luminance areas on the light intensity detection unit while moving the image, and corrects the position of the projection unit according to an output signal of the light intensity detection unit; A vehicle display device comprising the vehicle.   The focus adjustment unit corrects the position of the projection unit so that the difference between the maximum value and the minimum value of the output signal of the light intensity detection unit is maximized.

Images