KR950002286B1 - Liquid crystal display device - Google Patents

Abstract

The LCD improves a photo transmission efficiency in the LCD (liquid crystal display) forminng optical images according to image signals. The LCD comprises 1st/2nd polarization plates (5,11) polarizing parallel light generated from an optical source; 1st/2nd transparent base plates (3,4) arranged between polarization plates (5,11) by way of a liquid crystal layor (1); a transparent plate (42) having a micro lens array and a number of V shape grooves, positioned between the 1st polarization plate (5) and the transparent plate (3).

Description

LCD Display

1 is a cross-sectional view showing a part of a conventional liquid crystal display in detail.

2 is a schematic view of a conventional liquid crystal projection color display device.

3 is a cross-sectional view showing a part of the liquid crystal display of the present invention in detail.

4 is a cross-sectional view of the portion of FIG.

* Explanation of symbols for main parts of the drawings

1 liquid crystal layer 2 switching element

3: first transparent substrate 4: second transparent substrate

5: first polarizing plate 11: second polarizing plate

40: V type groove 41: Flat part

42 microlens array transparent plate 43 wiring of switching element

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projection type color display device, and in particular, in a liquid crystal display device that passes through three primary colors of red, green, and blue to form an optical image according to an image signal, and is suitable for improving light transmittance. .

1 is a cross-sectional view showing a part of a conventional liquid crystal display in detail, wherein a switching element 2 for driving the liquid crystal layer 1 between the first and second transparent substrates 3 and 4, which are the basis of the liquid crystal panel, is constant. It is formed at intervals, the first and second polarizing plates (5, 11) are formed on both sides of the first, second transparent substrates (3, 4), respectively, and is fixed between the second polarizing plate (11) and the first transparent substrate (3). Microlenses 6 are formed at intervals.

In addition, the transparent electrodes 9 and 10 arranged on both sides of the microlens 6 at regular intervals are connected to each other by the transparent electrode distributions 7 and 8, respectively, and the direct current power source Vcc is connected to the transparent electrode wirings 7 and 8. ) Is connected.

Referring to FIG. 2 of the prior art, the light of the light source 13 passes through the total reflection mirror 14, the blue light filter 15, the total reflection mirror 16, and the red light mirror 22. , 23 and 29 are focused to pass through each of the liquid crystal panel control panels 18 to 20, 24 to 26, and 30 to 32 in approximately parallel light to reach each of the liquid crystal panels 21, 27 and 33.

That is, the light is linearly polarized while passing through the first polarizing plate 5, irradiated to the microlens 6 via the transparent electrode 9, and then passes through the first transparent substrate 3 to reach the liquid crystal layer 1.

At this time, since the liquid crystal layer 1 is driven by the switching element 2 to polarize the incident light, the liquid crystal panels 21, 27, 33 of the liquid crystal panels 21, 27, and 33 which have passed through the second transparent substrate 4 and the second polarizing plate 11 in turn. Light is magnified by the projection lens 36 through the red light filter 28, the total reflection mirror 34, and the green light filter 35 to be projected onto the screen 37 to form an image.

In this case, the image brightness of the screen 37 is proportional to the intensity of light passing through each of the liquid crystal panels 21, 27, and 33, and the intensity of light emitted from each of the liquid crystal panels 21, 27, and 33 is the same. 13) is proportional to the light transmittance of each liquid crystal panel (21, 27, 33).

That is, the light passing through the first polarizing plate 5 is focused while passing through the microlens 6 having a predetermined refractive index by generating a predetermined potential difference between the transparent electrodes 9 and 10 by the DC power supply Vcc. Passes through the center of the liquid crystal layer (1).

However, in the conventional technique, the light focused in the microlens 6 passes through the center of the liquid crystal layer 1, but light incident on the boundary of the microlens 6 is not focused by the microlens 6. Without being cut off by the switching element 2 or the wiring of the switching element.

In this way, the amount of light that does not transmit can be roughly represented by the opaque band 12.

In addition, since the microlenses 6, the transparent electrodes 9 and 10, and the DC power supply are required, the cost increases, and incident light is also blocked by the transparent electrode wirings 7, 8.

The present invention has been made in view of such a conventional drawback, and an object thereof is to provide a liquid crystal display device having improved light transmittance.

Hereinafter, an embodiment of the present invention for achieving such an object will be described in detail with reference to the accompanying drawings.

3 shows a liquid crystal display device according to the present invention. The liquid crystal layer 1, the switching element 2, the first and second transparent substrates 3 and 4, and the first and second polarizing plates 5 and 11 are conventionally constructed. The light of the light source passes through the center of the liquid crystal layer 1 without being blocked by the switching element 2 or the wiring 43 of the switching element between the first polarizing plate 5 and the first transparent substrate 3. The V-shaped groove 40 and the flat portion 41 are formed so that the microlens array transparent plate 42 is alternately formed toward the light source side.

However, A, which is not described in the drawings, is an angle between the V-shaped grooves 40, D ₁ is the width of the V-shaped grooves 40, and D ₂ is a flat portion 41 to the center of the liquid crystal layer 1. Distance.

In the present invention as described above, the light emitted from the light source 13 passes through the total reflection mirror 14 through the blue light filter 15, the total reflection mirror 16, the red light mirror 22, and the like. It is separated into three primary colors of blue and focused on each condenser lens 17, 23, 29, whereby the image formed on the liquid crystal panels 21, 27, 33 is obtained by the red light filter 28, the total reflection mirror 34, and the green light filter 35. Are transmitted and reflected, respectively, and are enlarged by the projection lens 36 and projected onto the screen 37 as in the prior art.

According to the present invention having such a principle, approximately parallel light is focused in the condenser lens and linearly polarized through the first polarizing plate 5, and the V-shaped groove 40 formed on the light source side of the microlens array transparent plate 42 of such light is used. The incident light is refracted according to the width D ₁ and the angle A of the V-shaped groove 40 and is not blocked by the switching element 2 and the wiring 43 of the switching element. It penetrates (3) and enters into the center part of the liquid crystal layer 1.

In addition, the light incident on the flat part 41 of the linearly deflected light from the first polarizing plate 5 passes through the first transparent substrate 3 as it is and enters the central portion of the liquid crystal layer 1.

In order to realize such a light path, the equation is described with reference to FIG.

However, D ₃ to be used below is a distance from the V-shaped groove 40 to the end of the liquid crystal layer 1, D ₄ is a light blocking width, A ₁ is an angle between the repair line and the incident optical axis of the V-shaped groove 40, A ₂ is an angle formed by the repair line of the V-shaped groove 40 and the incident optical axis passing through the V-shaped groove 40, n ₁ is the refractive index of the first polarizing plate 5, and n ₂ is the microlens array transparent plate 42. and a refractive index, n ₃ is a refractive index of the first transparent substrate (3), n ₄ is the refractive index, and D ₅ of the liquid crystal layer (1) is the pitch of the liquid crystal cell.

In other words, in

Something like this In the relational equation, when A ₁ and A ₂ are sufficiently small, in Snell's law, n ₁ sinA ₁ = n ₂ sinA ₂ and n ₁ A ₁ = n ₂ A ₂ .

In addition, A = 2 × (90 ° -A ₁ ).

Therefore, the angle A between the V-shaped grooves 40 is

to be. The width D ₁ of the V-shaped grooves is such that the refracted light at the portion where the V-shaped groove 40 and the flat portion 41 meet is not caught by the light blocking width D ₄ .

Shall be.

In this way, the light incident through the two paths passes through the second transparent substrate 4 and the second polarizing plate 11 in turn and is finally projected onto the screen 37 by the projection lens 36 as the second degree.

The same effect can be obtained by forming the V-shaped groove 40 and the flat portion 41 on the light source side of the first transparent substrate 3 instead of forming the microlens array transparent plate 42.

As described above, the present invention forms a microlens array transparent plate 42 having the V-shaped groove 40 and the flat portion 41 formed between the first polarizing plate 5 and the first transparent substrate 3 so as to provide light transmittance. It can increase the cost and reduce the cost.

Claims (3)

First and second polarizing plates 5 and 11 for polarizing parallel light incident on parallel light from the light source side, and first and second polarizing plates 5 and 11 arranged through the liquid crystal layer 1. A plurality of V-shaped grooves 40 are formed between the two transparent substrates 3 and 4 and the first polarizing plate 5 and the first transparent substrate 3 at a light source side at a predetermined distance by the flat portion 41. And a microlens array transparent plate (42). The width D ₁ and the inter-angle A of the V-shaped groove 40 of the microlens array transparent plate 42 are the distance from the flat portion 41 to the center layer of the liquid crystal layer 1. A liquid crystal display device comprising the proper ratio according to (D ₂ ). The liquid crystal display device according to claim 2, wherein the width D ₁ is equal to or less than the pitch D ₅ of the liquid crystal cell minus the light blocking width D ₄ .