JP2995742B2 - Liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid crystal display device suitable for being disposed on a recruiting seat of an airplane, a passenger train or the like.

[Summary of the Invention]

The present invention relates to a liquid crystal display device that is preferably disposed on a reclining seat of an airplane, a passenger train, or the like, and includes a liquid crystal display disposed on a backrest of the reclining seat, a detecting unit that detects a reclining angle of the reclining seat, and a detecting unit. Control means for supplying a reclining angle detection signal to the liquid crystal display to control the luminance by changing the applied voltage, and controlling the upper and lower limit range determining means for determining the variable range of the applied voltage supplied to the liquid crystal display. And the amount of change in the viewing angle can be freely set.

[Conventional technology]

2. Description of the Related Art Conventionally, a display system in a passenger transport has been proposed in which a flat display is attached to the back of a seat back of an airplane, a passenger train, or the like so that passengers in a rear seat can enjoy TV images or obtain necessary information. I have. In general, a liquid crystal display is used as the flat display. As is well known, this liquid crystal display has a narrow allowable viewing angle range (directivity), and when the screen is viewed from an angle position outside the allowable viewing angle range, the image quality is greatly reduced. Since the seat back is usually of the reclining type, the screen viewing angle of the rear passenger changes depending on the reclining angle of the front seat, and deterioration of the image quality is inevitable.

In order to eliminate such adverse effects, the present applicant has previously published
Japanese Patent No. 142387 proposes a liquid crystal display control circuit that can always obtain a good image even when the tilt angle of the reclining seat changes. This liquid crystal display control circuit will be briefly described with reference to FIG. In FIG. 4, an input color video signal is processed by a luminance / chroma processing circuit (1) and decoded into three primary colors of red (R), green (G) and blue (B) signals, and then the liquid crystal display ( 2). The luminance / chroma processing circuit (1) has control terminals T1 and T2 for a luminance control input and a contrast control input. Outputs of the volumes VR1 and VR2 connected to the brightness adjustment knob and the contrast adjustment knob are supplied to control terminals T1 and T2 of the brightness / chroma processing circuit (1) via adders (3) and (4). Therefore, brightness and contrast can be adjusted by operating each knob.

The reclining angle signal output from the reclining angle detecting volume VR3 is supplied to luminance and contrast control terminals T1 and T2 in the luminance / chroma processing circuit (1) through adders (3) and (4). As a result, even if the screen viewing angle changes depending on the reclining angle, the directivity of the liquid crystal display (2) is automatically corrected in accordance with the angle, so that the image quality can be prevented from extremely lowering.
The addition ratio of each control by the brightness adjustment knob and the contrast adjustment knob and the control by the reclining angle detection can be determined by the resistors R1 and R2 and the resistors R3 and R4.

Reclining angle detecting volume VR ₃ above the liquid crystal display mounted on a shaft for rotation reclining is attached to the backrest of a reclining seat. FIG. 5 shows the configuration of the reclining angle detecting means. And fitting the gear (6) to the reclining rotary shaft (5) in FIG. 5, so fitted to the gear (6) and reclining engaging with gear (7) the angle detecting volume VR ₃ axes (8) is there. Now reclining rotary shaft (5) rotates the gear (6) (7) if rotated in the arrow A direction, to rotate the rotor of the reclining angle detecting volume VR _3,
Output terminal of the reclining angle detection volume VR ₃ (9)
If this output voltage is supplied to the adders (3) and (4) via the resistors R ₂ and R ₄ , the brightness and the contrast can be adjusted according to the reclining inclination angle.

[Problems to be solved by the invention]

According to the conventional configuration described with reference to FIGS. 4 and 5, the following disadvantages occur.

(A) When setting the amount of change of the viewing angle with respect to the reclining angle, the operating angle of the volume VR ₃ must be mechanically changed, and the amount of change of the viewing angle with respect to the reclining angle can be set freely. I can't do it.

(B) Depending on the type of liquid crystal display, for example, when a narrow viewing angle is obtained, the amount of change in the applied voltage must be increased, and the variation in the viewing angle of the liquid crystal display cannot be sufficiently covered.

Although can be set in the liquid crystal display or a single LCD (d) the same model, in different types of liquid crystal display can not be obtained detection means versatile different maximum and minimum values of the volume VR _3.

The present invention has been made in view of the above drawbacks, and its purpose is to set the optimum viewing angle at the maximum when the reclining seat is raised or lowered, and freely set the amount of change in the viewing angle. It is an object to obtain a liquid crystal display device that can be used.

[Means for solving the problem]

The liquid crystal display device of the present invention includes a liquid crystal display (2) for an example of which is disposed on the backrest of a reclining seat as shown in FIG. 1, the detecting means VR ₃ for detecting a reclining angle of a reclining seat,
The reclining angle detection signal from the detection means VR ₃ comprises a liquid crystal display supplied by changing the applied voltage to the (2) control means for controlling the brightness (10) to the liquid crystal display (2) upper and lower limit range determining means VR _5, the VR ₆ control means for determining the variable range of the applied voltage (1
0).

[Action]

According to the liquid crystal display device of the present invention, the control means (1
0) Variable range setting means VR ₅ , VR ₆ Volume VR ₅ , VR ₆
The viewing angle of the LCD display when the reclining seat is tilted and raised is adjusted optimally, and the reclining angle detection volume is adjusted within this adjusted range.
Since the VR ₃ moves within the range of the voltage difference between the volumes VR ₅ and VR ₆ according to the reclining, the liquid crystal display can be viewed in an optimal state at any reclining angle.

〔Example〕

Hereinafter, an embodiment of the liquid crystal display device of the present invention will be described with reference to FIGS.

FIG. 1 shows a control circuit of the liquid crystal display device of the present embodiment, and the same reference numerals are given to portions corresponding to those of FIG.

In FIG. 1, a video / chroma processing circuit (1) used in this embodiment is configured so that the luminance changes with a DC voltage.

The volume VR ₄ is arranged in the vicinity of the liquid crystal display (2) so that the user can directly turn it, and performs fine adjustment of the brightness, that is, the viewing angle. One end of the stator of the volume VR ₄ is connected to the voltage source Vcc, and the other end is connected to the ground potential via the resistor R _11. The mover of this volume VR ₄ is grounded via a series circuit of a resistor R ₅ → a volume R ₅ → a resistor R ₆ and a resistor R ₉ →
It is grounded through a series circuit of the volume VR ₆ → resistor R _10. In addition, the mover of this volume VR ₄ is connected to transistor Q ₁
And connected to the collector of each of Q _2, the transistor Q ₁
And Q ₂ each of the base connected to the movable element of the volume VR ₅ and VR ₆ above. This such transistors Q ₁ and Q ₂ each resistor emitter R ₇ and volume VR ₃ for reclining angle detection between both emitters with grounded through R ₈
Is connected to one end and the other end, respectively, and the movable element of the volume VR ₃ is connected to the luminance control terminal T _{1 of the} video / chroma processing circuit (1)
Connect to The volume VR ₃ for reclining angle detection is attached to the reclining rotary shaft (5) of the reclining seat (19) shown in Figure 3. Third
As shown in the figure, a liquid crystal display (2) is fixed to the back of the backrest (20) of the reclining seat (19). In FIG. 3, if the reclining handle (21) is moved upward in the direction of arrow D, the reclining lever (22)
Rotates clockwise around the fulcrum (23) against the biasing force of the spring (24), and is fitted to the gear (25) provided at the tip of the reclining lever and the reclining rotating shaft (5). The reclining seat (19) is disengaged from the gear (26), and the backrest (20) of the reclining seat (19) is opposed to the spring (27) constantly biased in the direction of the arrow E. When the reclining handle (21) is released, the backrest is inclined at a predetermined angle and the gear (25) and the gear (26) are engaged and fixed. This reclining the seat not shown the volume VR ₃ for reclining angle detecting may be attached to the volume VR ₃ in connection with the reclining rotary shaft (5). Although various mounting methods are conceivable, the mounting method may be, for example, as shown in FIG.

The operation of the liquid crystal display device of the present embodiment described above will be described with reference to FIG. FIG. 2 shows a drive waveform for AC driving the counter electrode of the liquid crystal panel of the liquid crystal display (2). The color video signal is applied to the opposite electrode of the liquid crystal panel alternately with a reverse polarity at a predetermined cycle around the reference line (11) of the AC signal, but FIG. 2 shows only the drive waveform in the positive direction. Volume of the pedestal (13) of the color video signal (12) in Fig. 2
Brightness of the liquid crystal display (2) by varying at VR ₃ is changed. First, the volume VR ₅ and the volume VR ₆ are used to adjust the viewing angle when the reclining seat (19) is raised up to the maximum and when the reclining seat (19) is folded down to the best condition, and differs depending on the type of the liquid crystal display (2). The brightness should be made darker when defeated, and brightened when raised. Of course, since the inclination angle varies depending on the type of the reclining seat, the viewing angle is adjusted to be optimal at the maximum and minimum inclination angle positions. Volume VR ₅ Thus, if the movable element position is set for the VR ₆ to the base of the transistor Q _1, Q ₂ is applied a predetermined bias voltage, the transistors Q _1, Q ₂ of each of the emitter and the resistor R _7, the connection point of each of R ₈ DC voltage is output. Since the volume VR ₃ is attached to the reclining rotation shaft (5) of the reclining seat (19) as described above, the movable element of the volume VR ₃ is a transistor Q ₁ according to the inclination angle of the reclining seat. Or Q
Volume VR ₃ moves to the direct voltage side caused the _second emitter within the emitter voltage difference between transistors Q _1, Q ₂
DC voltage is taken from the supply to the control terminal T ₁ of the video / chroma processing circuit (1), the luminance of the pedestal level voltage corresponding to the movement of the volume VR ₃ (13) is variable by a liquid crystal display (2) Changes. Volume VR ₄
View angle (luminance) values usually are in the central position determined the minimum voltage value determined by the maximum voltage value and the volume VR ₆ which defines the volume VR ₅ in that for fine adjustment for the user to adjust the since has become like that it can be shifted up and down while keeping to have been made as it is possible to adjust the viewing angle without changing the voltage range of the volume VR ₃ for reclining angle detection.

Since the liquid crystal display device of this example is configured and operates as described above, the optimal field of view when the reclining sheet is raised and tilted can be set for each reclining sheet, and the viewing angle can be set according to the reclining within the voltage variable range. Adjustment makes it possible to view the image on the liquid crystal display in an optimal state at any reclining angle. In addition, since the user sets the reference value of the optimum viewing angle without changing the viewing angle change amount with respect to the reclining angle, the user can view the image of the liquid crystal display (2) in an optimum state regardless of the height of the sitting height. I can do it.

It should be noted that the present invention is not limited to the embodiments described above, and can be variously modified without departing from the gist of the present invention.

〔The invention's effect〕

According to the liquid crystal display device of the present invention, the liquid crystal display can be viewed in an optimum state regardless of the angle of the reclining seat. In addition, it is possible to freely set the amount of change in the viewing angle with respect to the reclining angle.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a control circuit of the liquid crystal display of the present invention, FIG. 2 is a waveform explanatory diagram of the liquid crystal display of the present invention,
FIG. 3 is a side view of a main part of the reclining seat of the present invention,
FIG. 4 is a block diagram of a conventional liquid crystal display control circuit, and FIG. 5 is a block diagram of a conventional reclining angle detecting means. (1) is a video / chroma processing circuit, (2) is a liquid crystal display, (5) is a rotating shaft for reclining, (10) is a control circuit, and (19) is a reclining seat.

Claims (1)

(57) [Claims] 1. A liquid crystal display disposed on a backrest of a reclining seat, a detecting means for detecting a reclining angle of the reclining seat, and a reclining angle detection signal from the detecting means being supplied to the liquid crystal display to apply an applied voltage. Control means for changing the luminance to control the brightness, and a variable range determining means for determining an upper limit and a lower limit range of the applied voltage supplied to the liquid crystal display is provided in the control means. Liquid crystal display device.