JP2000250426A - Projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection liquid crystal display device connecting a driving circuit with a liquid crystal display panel without using a flexible substrate. SOLUTION: This is a projection liquid crystal display device provided with a liquid crystal panel 13, a circuit substrate 12 provided with a driving circuit for driving the liquid crystal panel, a projection lens indication body having a projection lens for magnifying an image and projecting it onto the liquid crystal panel, and a holder which holds the liquid crystal display panel and fixes it on the circuit substrate, and further has a 1st positioning part for positioning the panel at the time of connecting it with the projection lens indication body, and the electrodes arranged on the liquid display panel 13 are electrically connected with a connector arranged on the holder, and the holder and the projection lens are positioned by the positioning part and connected with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device, and more particularly to a projection type liquid crystal display device which enlarges and projects a modulated image on a liquid crystal panel.

[0002]

2. Description of the Related Art FIG. 12 is a block diagram of a conventional projection type liquid crystal display device. 12, the projection type liquid crystal display device includes a liquid crystal panel 102, a driving circuit 104 for driving the liquid crystal panel 102, an input / output wiring (harness) 105 of the driving circuit 104, the driving circuit 104 and the liquid crystal panel 102.
And a projection lens unit 101 for projecting an image based on an image signal output via the flexible wiring 103.

[0005] The liquid crystal panel 102 is closely fixed to the projection lens unit 101 so that the optical axis and the focus are aligned. The alignment between the projection lens unit 101 and the liquid crystal panel 102 is performed by the liquid crystal panel 10.
2 is carried out while viewing an image based on the output image signal.

The drive circuit 104 not only drives the liquid crystal panel 102 but also amplifies and outputs a display signal received from a substrate (not shown) via a harness 105. The length of the flexible wiring 103 is determined in accordance with the arrangement of the driving circuit 104 and the position of the connection part of the wiring. The connection part of the flexible wiring 103 of the drive circuit 104 is usually
It is provided at a position relatively close to liquid crystal panel 102.

[0005]

However, the conventional projection-type liquid crystal display device configured as described above has the following problems.

In a conventional projection type liquid crystal display device, a liquid crystal panel 102 and a projection lens unit 101 are aligned and fixed to each other in close contact. for that reason,
Each time the liquid crystal panel 102 or the like is replaced, the fixed liquid crystal panel 102 and the projection lens unit 10 are replaced.
1 and had to be removed. Then, the troublesome alignment had to be performed again.

Further, in order to improve the image quality of an image displayed by the projection type liquid crystal display device, for example, it is conceivable to increase the number of pixels of a liquid crystal panel. When the number of pixels of the liquid crystal panel 102 is to be increased, the
4 needs to be redesigned, and the projection type liquid crystal display device needs to be remanufactured. Then, since the size and shape of the drive circuit are changed, it is necessary to arrange all the components of the projection type liquid crystal display device on the drive circuit board 104 again.

Further, the flexible substrate 103 includes:
Usually, it is composed of a plurality of conductors and an insulating material surrounding the conductors. Therefore, the antenna becomes an antenna against electric noise (especially, radiation noise from a high-voltage portion such as a power supply circuit (not shown)). Therefore, the flexible substrate 103
Is likely to have electrical noise. This noise disturbs the image signal or the drive pulse, and thus causes deterioration of the image quality of the image.

Further, the flexible wiring 103 oscillates a noise proportional to the LC product by the capacitance component C and the inductance L of the flexible wiring 103 itself. This becomes particularly noticeable as the number of pixels of the liquid crystal panel 102 increases and the driving frequency increases. Therefore, it is difficult to increase the image quality by increasing the number of pixels.

Further, the projection type liquid crystal display device of the prior art outputs an image signal from the drive circuit 104 to the liquid crystal panel 102. This image signal was often an analog signal. However, in recent years, a projection type liquid crystal display device using an image signal as a digital signal has become mainstream. The number of pins of the flexible wiring 103 used in the projection type liquid crystal display device that handles digital signals is 100 or more. At present, there is no single flexible wiring 103 that can cover 100 pins. Therefore, it is necessary to provide several flexible wirings 103 in the projection type liquid crystal display device.

[0011]

According to the present invention, there is provided a display panel, a circuit board having a drive circuit for driving the display panel, and an image projected on the display panel in an enlarged manner. A projection lens support having a plurality of projection lenses, and a holder having a first positioning portion for holding and fixing the display panel to the circuit board and further positioning when connecting to the projection lens support In a projection display device, an electrode provided on the display panel and a connector provided on the holder are electrically connected, the connector is electrically connected to the circuit board, and the holder and The projection lens is positioned and connected by the positioning section.

That is, since the liquid crystal panel, the connector, and the circuit board are connected, and the holder and the projection lens are connected, the components of the liquid crystal device are integrated.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of a projection type liquid crystal display device of this embodiment. In FIG. 1, the exchange unit 42
Is a liquid crystal panel and a driving circuit (both not shown) described later.
And a single printed circuit board board (printed ci
rcuit board; hereinafter, referred to as PCB. ) 42a and P
And a shield plate 42b for preventing radiation noise that covers the exposed surface of the CB 42a. Replacement unit 4
2 has a connection terminal 42c for harness connection, and is connected to an external interface and a power supply circuit board (both not shown).

As will be described later, the projection lens unit 41 has a projection lens unit 41a and a polarization beam splitter unit 41b for polarizing incident light. The projection lens unit 41 and the exchange unit 42 are positioned at desired positions.

FIG. 2 is an exploded perspective view showing a liquid crystal display panel mounting portion according to the liquid crystal display device of this embodiment. In FIG. 2, reference numeral 11 denotes a liquid crystal display panel (L
CD) socket, 12 is a circuit board on which peripheral circuits for driving the liquid crystal display (LCD) panel 3 are mounted, 13 is a liquid crystal display (LCD) panel, and 14 is a liquid crystal display panel 13 which is pressed against the liquid crystal display panel socket 11. A pressing plate / radiator plate for radiating heat from the liquid crystal display panel 13;
Is a hook attached to the liquid crystal display panel socket 11 via the circuit board 12, the liquid crystal display panel 13, and the pressing plate / radiator plate 14, and 16 is a fixing screw for attaching the liquid crystal display panel socket 11 to the circuit board 12.

The four legs of the hook 15 are fitted into the grooves of the liquid crystal display panel socket 11, and the hook 15 is attached to the liquid crystal display panel socket 11. The liquid crystal display panel socket 11 is fixed to the circuit board 12 with a fixing screw 16 in advance.
The liquid crystal display panel socket 11, the circuit board 12, the liquid crystal display panel 13, the pressing plate and heat sink, and the hook 15 are integrated by mounting the hook 15.

The LCD socket 11 has, for example, a convex portion for positioning when connected to the beam splitter portion 41b of the projection lens unit 41. The positioning portion may have a shape such as a groove.

FIG. 3 is a perspective view showing a state where the liquid crystal display panel socket is mounted on the circuit board. As shown in FIG. 3, the liquid crystal display panel socket 11 is
Is attached to the base with fixing screws 16. Also, a state is shown in which the four legs of the hook 15 are fitted and fitted in the grooves of the liquid crystal display panel socket 11.

FIG. 4 is a perspective view showing a state in which the pressing plate / radiator plate 14 is attached by a hook. As shown in FIG.
Is attached. The pressing plate and heat sink 14 is provided with a groove in order to enhance heat dissipation efficiency.

FIG. 5 is a sectional view of the liquid crystal display panel mounting portion for showing the mounting state. Electrical connection between the liquid crystal display panel 13 and the circuit board 12 is performed by connecting a contact terminal (connector) 17 provided in the liquid crystal display panel socket 11 serving as a holder and an electrode of the liquid crystal display panel 13. . The electrodes of the liquid crystal display panel 13 are taken out on two sides of the panel, and are connected to the contact terminals 17 provided according to the number of electrodes on the two sides of the liquid crystal display panel. The contact terminals 17 and the circuit board 12 are not only brought into contact with each other, but also connected with solder so that electrical connection is reliably performed. The connection between the electrode of the liquid crystal display panel 13 and the contact terminal 17 is made by the hook 1
5, the pressing plate / radiator plate 14 is pressed, and the liquid crystal display panel 13 is further pressed via the pressing plate / radiator plate 14 to make contact with the contact terminals 17 connected to the circuit board 12 in advance. You. The connection with solder may be performed after the hook 15 is attached.

Contact terminal 17 and liquid crystal display panel 13
It is desirable that the electrode is contacted with a load of 50 g or more per pin. In addition, the electrodes of the liquid crystal display panel 13 are previously provided with a corrosion prevention coat,
By breaking this at the time of contact with the electrode, corrosion of the electrode can be prevented.

Between the liquid crystal display panel 13 and the pressing plate and heat radiating plate 14, a heat radiating silicone 18 is provided to enhance heat radiating properties.
Is provided. The upper portion of the pressing plate / radiator plate 14 (on the side where the liquid crystal display panel is disposed) has a concave shape so as not to affect the cell gap of the liquid crystal display panel 13.
The heat radiation silicone 18 is placed in the concave portion of the concave shape portion.

FIG. 6 shows a projection lens unit used in the liquid crystal display device of this embodiment. FIG. 6A is a diagram showing a cross-sectional view of the projection lens unit from above. FIG. 6B is an external view of the projection lens unit. As shown in FIG. 6A, a plurality of lenses are provided inside the projection lens unit 41a. The polarization beam splitter 41b includes a polarization beam splitter and FIG.
(B) a window through which light enters from below.

As shown in FIG. 6B, the polarizing beam splitter 41b has a concave portion for positioning when connected to the LCD socket 11 provided on the LCD driving circuit board 12. ing. Further, it has a screw hole for attaching the optical solid fixing screw 16.
In addition, the shape of the positioning portion is not limited to the concave portion, and may be, for example, a groove.

Light incident from the window of the polarization beam splitter section 41b is incident on the polarization beam splitter. For example, the polarizing beam splitter transmits S-polarized light,
One that reflects P-polarized light is used. The reflected P-polarized light is
As will be described later, a liquid crystal panel (not shown) is illuminated.

FIG. 7 is a diagram showing a PCB and a projection lens unit. Note that the shield plate 42b is omitted for convenience of explanation. The state before connecting the polarization beam splitter part 41b and the LCD socket 11 is shown. As described above, the connection position between the polarization beam splitter portion 41b and the LCD socket 11 is determined by the concave portion and the convex portion, and is attached by the optical solid fixing screw 16, and the projection type liquid crystal as shown in FIG. It becomes a display device.

FIG. 8 is a schematic view of a main part of an optical system of an example of a projection type liquid crystal display device using the liquid crystal display device of this embodiment. FIG. 8A is a top view of the liquid crystal display device, and FIG.
8B shows a front view, and FIG. 8C shows a side view.

In this embodiment, a liquid crystal panel 2 with microlenses is used, and a reflection type liquid crystal panel that can modulate three colors of R, G, and B with one panel is used. The liquid crystal panel provided in the projection type liquid crystal display device is not limited to the liquid crystal panel with microlenses 2, but may be a normal liquid crystal panel to which a color filter is attached.

If the optical arrangement is changed, a transmissive liquid crystal panel can be used. Further, two or three transmissive liquid crystal panels or reflective liquid crystal panels that do not use microlenses and color filters can be used.

In FIG. 8, reference numeral 1 denotes a projection lens, and a panel (liquid crystal panel) 2 using a liquid crystal with a microlens.
Is projected on a predetermined surface. Reference numeral 3 denotes a polarizing beam splitter (PBS) that transmits, for example, S-polarized light and reflects P-polarized light.

Reference numeral 40 denotes an R (red light) reflecting dichroic mirror; 41, a B / G (blue & green light) reflecting dichroic mirror; 42, a B (blue light) reflecting dichroic mirror; Reflection mirror, 50
Is a Fresnel lens, 51 is a convex lens (positive lens), 6 is a rod-type integrator, 7 is an elliptical reflector.

Here, a description will be given in accordance with the progress of the light beam emitted from the light source 8. First, the white light beam emitted from the lamp 8 is condensed at the entrance (incident surface) 6 a of the integrator 6 by the elliptical reflector 7. Then, the light travels while being reflected in the integrator 6. As the light is reflected in the integrator 6, the spatial intensity distribution of the light beam is made uniform. Then, the light beam emitted from the emission port 6b of the integrator 6 is converted into a parallel light beam in the x-axis direction (based on FIG. 8B) by the convex lens 51 and the Fresnel lens 50, and the B reflection dichroic mirror 42. Leads to.

In the B reflection dichroic mirror 42,
Only light (blue light) is reflected, and travels toward the R reflection dichroic mirror 40 at a predetermined angle with respect to the z axis in the z-axis direction, that is, on the lower side (reference to FIG. 8B). On the other hand, the color light (R light / G light) other than the B light passes through the B reflection dichroic mirror 42, is reflected by the high reflection mirror 43 at right angles in the z-axis direction (downward), and is reflected by the R reflection dichroic mirror 4.
Go to zero.

Here, the B reflection dichroic mirror 42
8A, the light flux from the integrator 6 (x-axis direction)
Is arranged to be reflected in the z-axis direction (downward).
The high reflection mirror 43 is disposed at an inclination of exactly 45 ° with respect to the xy plane with the y-axis direction as a rotation axis. On the other hand,
The B reflection dichroic mirror 42 is arranged at an angle smaller than 45 ° with respect to the xy plane with the y-axis direction as the rotation axis.

Therefore, the R / G light reflected by the high reflection mirror 43 is reflected in the z-axis direction. On the other hand, the B light reflected by the B reflection dichroic mirror 42 goes downward at a predetermined angle (tilt in the xz plane) with respect to the z axis. Here, the liquid crystal panel 2 of B light and R / G light
In order to match the upper illumination range, the shift amount and the tilt amount between the high reflection mirror 43 and the B reflection dichroic mirror 42 are selected so that the principal rays of each color light intersect on the liquid crystal panel 2.

Next, as described above, the downward direction (z-axis direction)
The R / G / B light heading toward is directed toward the R reflection dichroic mirror 40 and the B / G reflection dichroic mirror 41. These are arranged below the B reflection dichroic mirror 42 and the high reflection mirror 43. The B / G reflection dichroic mirror 41 is arranged at an angle of 45 ° with respect to the xz plane about the x axis as the rotation axis. The R reflection dichroic mirror 40 is set at an angle smaller than 45 ° with respect to the xz plane with the x-axis direction as the rotation axis.

Therefore, R / G / B incident on these
Of the light, the B / G light is the R reflection dichroic mirror 40
, Is reflected by the B / G reflection dichroic mirror 41 at right angles in the y-axis + direction, is polarized through the PBS 3, and is then horizontally disposed on the xz plane.
To illuminate.

On the other hand, the B light is emitted as described above (FIG. 8).
(A), see FIG. 8 (b)) Since the light travels at a predetermined angle (tilt in the xz plane) with respect to the already-formed x-axis, after reflection by the B / G reflecting dichroic mirror 41, A predetermined angle (tilt in the xy plane) is maintained, and the angle is set as an incident angle (in the xy plane direction) to illuminate the liquid crystal panel 2.
The G light is reflected at right angles by the B / G reflection dichroic mirror 41, travels in the positive y-axis direction, is polarized through the PBS 3, and then illuminates the liquid crystal panel 2 at an incident angle of 0 °, that is, vertically.

As for the R light, the B /
R arranged in front of the G reflection dichroic mirror 41
The reflection dichroic mirror 40 reflects the light in the y-axis + direction on the R reflection dichroic mirror 40.
(C) As shown in (side view), the beam travels in the y-axis + direction at a predetermined angle (tilt in the yz plane) with respect to the y-axis,
After being polarized through the liquid crystal panel 2, the liquid crystal panel 2 is illuminated with the angle with respect to the y-axis set as an incident angle (yz plane direction).

As described above, in order to make the illumination ranges of the R, G, and B color lights on the liquid crystal panel 2 coincide with each other, the B / G reflections are made so that the principal rays of each color light intersect on the liquid crystal panel 2. The shift amount and the tilt amount between the dichroic mirror 41 and the R reflection dichroic mirror 40 are selected.

FIG. 9 is a block diagram of a liquid crystal display panel and a driving circuit for driving the panel. The drive circuit shown in FIG. 9 integrates, on a single substrate, at least the blocks required for an electric circuit from an external image signal input to a liquid crystal display panel.

In FIG. 9, a liquid crystal display panel 22 and an ASIC 23 for performing signal correction, image processing, gamma correction processing, and the like on a digital image signal, and sending the processed signal to the liquid crystal display panel 22 on one substrate 21. , R, G, and B analog image signals are converted into digital image signals, and AS
A / D converters 24a, 24b, 24c to be sent to the IC 23,
A preamplifier 25 for analogly amplifying an image input signal from the outside, a synchronization pulse of the external signal is detected, the synchronization pulse is locked, and the ASIC 23 and the AD converters 24a to 24c are locked.
(Phase Locked Loop) to supply synchronization pulse to
SGRAM (Snychronous Graphic RAM) 2 for temporarily storing a signal being processed before and after processing by the circuit 26 and the ASIC 23
7a, 27b, 27c, SGRAM, ASIC, TG (Timing G
enerator) 28 and the like are implemented. SGRAM is 3
Although the number is used, this number varies depending on the type of processing required.

The number shown on the signal path in FIG.
Using an it's AD (twist pair twice the number of lines) converter,
This is an example of the number of lines in the case of a digital panel having the number of pixels of XGA (1024 × 768), and this number changes depending on the panel specifications and the number of AD conversion bits.

FIG. 10 shows a configuration example of a liquid crystal display panel. In this embodiment, an example of a so-called "digital panel" in which a shift register is provided on a chip around a display area and further has a built-in D / A converter for converting a digital input signal into an analog signal has been described.

In FIG. 10, the display area 31 is composed of a large number of pixel switches in a matrix. The horizontal shift registers 32a and 32b output timings for writing digital image signals from above and below, respectively, in the display area. In order to prevent burn-in of the liquid crystal, for example, the shift register 32a operates during the odd field, the shift register 32b pauses, and vice versa during the even field. In the odd field, the positive signal line 33a supplies a digital signal to the latch. The latch 34a receives the timing from the shift register 32a and converts the stored digital signal into a positive-polarity DAC (Digital-Analog DAC).
onverter) group 35. The positive polarity DAC 35 writes the offset-corrected signal in the display area. Offset correction ADC (Analogue-Digital converter) 37a
Has a role of correcting a DAC offset measured in advance with reference to a reference voltage, and correcting and calculating a signal of the positive polarity DAC into a signal having no offset. Reference voltage circuit 38a
Supplies a reference voltage serving as a reference for determining the offset amount to the offset correction ADC 37a.

In the even field, the function of the image signal line 33a in the odd field is controlled by the image signal line 33b, and the function of the latch 34a is controlled by the latch 34b.
The function of the negative polarity DAC 36 is performed by the offset correction ADC 3.
The function of FIG. 7a is offset corrected by the reference voltage circuit 3b.
The reference voltage circuit 38b performs the same operation as the reference voltage circuit 38b.

FIG. 11 is a schematic diagram of a layout diagram of a circuit chip of the liquid crystal display panel of FIG. As in FIG. 9, a shift register is formed around the display area, and a D / A converter for converting a digital signal into an analog signal is also provided.

On the short side of the panel, there are provided electrodes for inputting signals. In consideration of the positional deviation when the panel is mounted on a socket, the size of the panel is 0.3 × 0.5 mm and the distance is 0.5 mm. installed. Electrodes of 52 pins were arranged on one side and 104 pins were arranged on both sides.

The display panel used in the present invention is not limited to a liquid crystal. DMD (Digit) of mechanical light modulation system
al. Mirror Device).

[0051]

According to the present invention, the display panel can be directly mounted on the circuit board on which the drive circuit is mounted and integrated, and the connection between the drive circuit and the display panel can be made without using a flexible substrate. The display panel can be upgraded and the display device can be maintained.

Further, when the display panel is upgraded, components other than the circuit board in the display device can be removed and reused, so that the recyclability of the product is improved, the waste is suppressed, and the earth is reduced. It also contributes to environmental protection on a scale.

Further, according to the present invention, the holder is provided with the positioning portion, and the positioning is performed by the positioning portion to connect the holder and the projection lens. Therefore, alignment between the projection lens and the liquid crystal display panel can be easily performed.

[Brief description of the drawings]

FIG. 1 is an external view of a projection type liquid crystal display device.

FIG. 2 is an exploded perspective view showing a liquid crystal display panel mounting portion relating to the liquid crystal display device.

FIG. 3 is a perspective view showing a state in which a liquid crystal display panel socket is attached to a circuit board.

FIG. 4 is a perspective view showing a state in which a pressing plate and a heat sink are attached by hooks.

FIG. 5 is a cross-sectional view of a liquid crystal display panel mounting portion for showing a mounting state.

FIG. 6 is a diagram showing a projection lens unit used for a liquid crystal display device.

FIG. 7 is a diagram showing a PCB and a projection lens unit.

FIG. 8 is a schematic diagram of a main part of an optical system of an embodiment of a dosing type liquid crystal display device using the liquid crystal display device.

FIG. 9 is a block diagram of a liquid crystal display panel and a driving circuit for driving the panel.

FIG. 10 is a configuration diagram of a liquid crystal display panel.

11 is a schematic diagram of a layout diagram of a circuit chip of the liquid crystal display panel of FIG. 9;

FIG. 12 is a configuration diagram of a conventional projection display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Liquid crystal display panel (LCD) socket 12 Circuit board 13 Liquid crystal display (LCD) panel 14 Pressing plate and heat sink 15 Hook 16 Fixing screw 17 Contact terminal (connector) 18 Heat dissipation silicone

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03B 21/00 G03B 21/00 D 33/12 33/12

Claims (7)

[Claims] 1. A display panel, a circuit board having a drive circuit for driving the display panel, a projection lens support having a projection lens for enlarging and projecting an image on the display panel, and holding the display panel And a holder having a first positioning portion for positioning when connecting to the projection lens support, and an electrode provided on the display panel and a connector provided on the holder Wherein the connector is electrically connected to the circuit board, and wherein the holder and the projection lens are positioned and connected by the positioning portion. apparatus. 2. The projection display apparatus according to claim 1, wherein the holder is attached to the circuit board, and the display panel is held by the holder by being pressed by the holder. . 3. The projection type display device according to claim 1, wherein the first positioning portion provided on the holder is provided on a surface on the projection lens support side. 4. The projection type display device according to claim 1, wherein the projection lens support includes a second positioning section corresponding to the first positioning section on a surface on the projection lens side. 5. The projection type display device according to claim 1, wherein the electrodes of the display panel are extended to two sides of the display panel. 6. The projection display device according to claim 1, wherein the circuit board includes a circuit that converts an image signal output to the panel into a digital signal. 7. A display panel, a circuit board provided with a drive circuit for driving the display panel, a projection lens support having a projection lens for enlarging and projecting an image on the display panel, and a first positioning section. A projection type display device, comprising: a holder having the first positioning portion, wherein the display panel and the projection lens support are mounted on the circuit board with the same fixing screw.