JPH07102788B2 - Head up display - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention makes a safety confirmation video camera arranged behind and at the left and right ends of a vehicle such as an automobile or a one-man vehicle easy to see even when it is backlit, and also has a plurality of videos. The present invention relates to a head-up display that makes it easy to see camera images by switching them in good timing.

2. Description of the Related Art A head-up display (hereinafter, referred to as HUD) is, for example, in an airplane cockpit, where the operator can confirm necessary information without having to direct his or her line of sight from the steering direction to the dashboard. It is known from US Pat. No. 4,218,11 (1980). Meanwhile, U.S. Pat.
No. 100 (1972) discloses a combination of a sighting crosshair and a camera image in a HUD equipped with a fighter. Fig. 4 shows the one that appeared for automobiles (conventional example), and has an electronic shutter LCD19 that displays information in the dashboard.
Light source 20 that illuminates the rear side of the
The optical system 21 that magnifies the surface image of the
22 is attached to the inner surface of the windshield 23.

However, in any of the above-mentioned conventional examples, the on-board camera image is captured by the HU.
If you try to display it on D, for example, if the headlights of another vehicle come in with backlight at night, there is a drawback that the dark part will sink or the contrast will not be achieved due to insufficient DC transmission amount of the automatic diaphragm mechanism of the camera and the amplification system. It was Further, for example, when displaying the images of the two left and right safety confirmation cameras arranged on the left and right ends of the vehicle body, two displays are required, and when the images are displayed on one display, they are small and difficult to see. there were.

In view of the above-mentioned problems of the conventional example, the present invention intends to add a front circuit for compressing a backlight part and expanding a dark part, or to actively select and switch a plurality of video camera images in real time for actual shooting. To do.

Means for Solving the Problems In order to achieve the above object, the present invention provides a HUD signal input stage,
It is characterized by providing a non-linear processing circuit capable of compressing the white peak side and expanding the dark portion.

In addition, the rear confirmation camera image is switched only when the back gear is turned on, and moreover, it is brighter than during normal driving and is actually shot on the HUD.

Further, the left and right confirmation camera images are actually shot only when the turn indicator blinkers are being output, and the left and right camera images are alternately switched in synchronism with the turn signal cycle to be actually shot on the HUD.

Operation According to the above configuration, a human figure that is difficult to see because it is hidden by the shadow of the headlight of a car approaching at night also rises and the contrast is clearly visible.

In addition, the rear view camera image is brighter and more visible when moving backward, as compared with normal forward running.

In addition, the left and right confirmation camera images can be taken in real time on a single HUD screen in synchronization with the turn signal cycle, as if humans were looking at the left and right to confirm safety, and a large live view can be secured, ensuring safety. To be done.

EXAMPLE An example in which the present invention is mounted on, for example, an automobile will be described with reference to FIGS. FIG. 1 is a block diagram of this embodiment. The output signal from the camera passes through the non-linear processing circuit 1 and HUD2 to the windshield surface (display surface).
It is projected on 3. The non-linear signal processing circuit 1 provided in the input stage of the HUD 2 is a circuit which produces an output signal 5'when an input signal 5 is applied as shown in FIG. 2 (a). That is, the headlight light 8-9 on the side of the white peak 10 is compressed and 8'-
At 9 ', the dark portions 6 to 7 are stretched to become 6'to 7'and float up, and at the same time, they are easy to see with contrast.

A principle diagram for obtaining the non-linear characteristic 11 is shown in FIG. NPN
The cathode side of the non-linear element D is connected to the collector of the transistor TR, and the non-linear characteristic in which the smaller the current of the non-linear element D is, the higher resistance value is used. That is, the input waveform V
_{Since the} TR current is small _{in the} in dark portion and the resistance value of the non-linear element D is large, the load resistance of TR increases and the amplification degree increases, and the output waveform V _OUT is extended like the dark portion. On the contrary, the bright part is compressed. Note that r ₀ and r _c are the emitter resistance and the collector resistance. R ₁ and R ₂ are voltage dividing resistors.

Video output rearview camera R _c (FIG. 1) is applied via the switch SW ₂ is photographed I switched only when back Gya put into the non-linear signal processing circuit 1. At this time, since it is intended to move backward, the HUD is devised so as to obtain an image brighter than the brightness during normal driving.

Left and right confirmation camera FC _L, the video output of FC _R (FIG. 1) is switched alternately by a switch SW ₁ which is synchronized with the direction indicator turn signal. For example, in the case of left turn the manner switched to camera FC _L side of the left when being displayed arrow 12 left as FIG. 3 (b), have an arrow as left of FIG. 3 (c) is displayed When not in use, it is synchronized with the turn signal so that it switches to the right side camera FC _R side. Furthermore, in FIG. 3 (b) 13,
It is also preferable to simultaneously perform the real-time shooting direction identification display which is aimed by the camera as in 18 in (c). The output of SW ₁ goes through SW ₂ and is corrected by the non-linear signal processing circuit 11 and HUD
It was taken live in 2. Or nonlinear signal processing circuit 1 rearview camera R _c, left and right check cameras FC _L, are effective for operated at all times to the video output of Izure FC _R.

On the other hand, the rear confirmation camera Rc and the left and right confirmation cameras FC _L and FC _R can be separately adopted as feature differences depending on the vehicle type, but it is more effective to use all the confirmation cameras as a system.

EFFECTS OF THE INVENTION According to the present invention, it is possible to actually shoot a camera image that can recognize well the dark part of the shadow that was difficult to see with a headlight, etc. to the HUD, the rear camera image is bright, and the left and right confirmation cameras are also optimally switched to the HUD with good visibility. You can live-action.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, FIG. 1 is a block diagram thereof, FIGS. 2 (a) and 2 (b) are characteristic diagrams and principle diagrams of a non-linear signal processing circuit, and FIG. 3 (a). ) Is a rear confirmation camera image output diagram, FIGS. 3 (b) and (c) are left and right confirmation camera image output diagrams, and FIG. 4 is a configuration diagram of a conventional example of the HUD. 1 ... Non-linear signal processing circuit, 2 ... HUD, 4 ... Car body, Rc ... Rear view camera, _FCL ...... Left view camera, F
C _R ...... right confirmation camera, SW ₁ · SW ₂ ...... video selection changeover switch, 5 ...... input signals, 6-7 ...... dark portion of the signal, 8
9 ... White peak side signal, 10 ... White peak, 11 ... Non-linear signal processing circuit input / output characteristic curve, 12 ...
… Left turn display arrow, 13,18 …… Camera shooting direction identification display, 1
5 …… Person, 16,19 …… Headlights of other vehicles.

Claims (4)

[Claims] 1. A head-up display for displaying a video input signal through a non-linear signal processing circuit for partially compressing and expanding the video input signal. 2. The head-up display according to claim 1, wherein the non-linear signal processing circuit is a circuit capable of compressing a white peak side of a video camera image input and expanding a dark portion. 3. The head-up display according to claim 1, wherein the rear view video camera image is switched only when a back gear is inserted when the vehicle body is moved backward, and the image is made brighter than during normal driving. 4. A left-right safety confirmation video camera image disposed on the left and right ends of the vehicle body when the vehicle approaches a crossing point where visibility is poor, and the images are alternately switched to the right and left in synchronism with the cycle of a turn indicator blinker. Head-up display.