Printing apparatus
By combining the dimming panel and the backlight source, the transmittance of the backlight in multiple dimming zones is controlled, which solves the control complexity problem caused by the high-frequency switching of the laser print head, achieves more efficient printing speed and reduces the power consumption of the light source component.
Patent Information
- Application Number
- CN202511099846.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2025-10-21
AI Technical Summary
Existing laser print heads require high-frequency switching, which makes control complex and the control of light source components difficult.
A dimming panel and backlight combination is used to control the transmittance of the backlight in multiple dimming areas through the dimming panel, forming multiple exposure beams to directly expose multiple points on the photosensitive drum, reducing the number of switching times of the dimming panel.
The control difficulty of the light source component is reduced, the printing speed and exposure efficiency are improved, and the power consumption of the light source component is reduced.
Smart Images
Figure CN120821170A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of printing technology, and in particular to a printing device. Background Art
[0002] A printer is a common device that quickly prints high-quality text and graphics on plain paper. It consists of a light source assembly and a photosensitive drum. The printer's operation involves modulating the image information to be printed into a light beam emitted by the light source assembly. This light beam then shines on the photosensitive drum, removing negative charges from the exposed areas of the drum. The positive charge then attracts the negatively charged toner, forming a toner pattern on the drum. Finally, the toner pattern is transferred to the paper, and the toner on the paper is fixed.
[0003] Currently, the light source component is typically a laser print head. When the laser beam strikes the photosensitive drum, it scans the drum point by point, forming a fine dot matrix. This point-by-point scanning requires the laser print head to be frequently switched on and off, making its control more complex. Summary of the Invention
[0004] The embodiments of the present application provide a printing device that reduces the difficulty of controlling a light source assembly, thereby at least partially solving the above-mentioned technical problems.
[0005] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, there is provided a printing device, comprising a light source assembly and a photosensitive drum. The light source assembly comprises a dimming panel and a backlight source. The dimming panel is located on the light-emitting side of the backlight source and has a plurality of dimming zones. The backlight source is configured to emit backlight to the interior of the dimming panel. The dimming panel is configured to control the transmittance of the backlight in each of the dimming zones based on image data to form an exposure light beam. The photosensitive drum is located below the light source assembly, and the surface of the photosensitive drum is configured to form a charge layer, and after the charge layer is exposed by the exposure light beam, the surface loses the charge of the exposed area to form a charged latent image on the surface.
[0006] Optionally, the dimming panel includes a liquid crystal component, and the liquid crystal component includes a plurality of liquid crystal molecules.
[0007] Optionally, the response time of the liquid crystal molecules is less than or equal to 500 μs.
[0008] Optionally, the plurality of liquid crystal molecules include ferroelectric liquid crystal material.
[0009] Optionally, the liquid crystal assembly does not include a color filter layer.
[0010] Optionally, one working cycle of the light source assembly includes a liquid crystal response period of the liquid crystal assembly and a light emitting period of the backlight source; in one working cycle, the light emitting period is later than at least part of the liquid crystal response period.
[0011] Optionally, the printing device further includes a collimating lens, which is located on the light-emitting side of the light source assembly and is arranged corresponding to the dimming zone.
[0012] Optionally, the dimming panel further includes a light-shielding layer, the light-shielding layer includes a light-transmitting opening and a light-shielding portion, the light-shielding portion overlaps with a gap between adjacent dimming zones, and the light-transmitting opening overlaps with the dimming zone.
[0013] Optionally, the collimating lens has a light incident surface, and the shape of the light-transmitting opening is the same as that of the light incident surface.
[0014] Optionally, the printing device further includes a developing assembly, a transfer assembly, and a fixing assembly. The developing assembly is configured to deliver toner to the surface of the photosensitive drum, causing the toner to be acted upon by the charged latent image to form a toner pattern on the surface of the photosensitive drum. The transfer assembly is configured to bring a printing substrate into contact with the photosensitive drum to transfer the toner image onto the printing substrate. The fixing assembly is configured to heat the printing substrate so that the toner image forms a print pattern on the printing substrate.
[0015] In the printing device of the present embodiment, compared to a laser print head that can only scan one point at a time, requiring frequent switching, the dimming panel of the present embodiment can simultaneously control the transmittance of the backlight through multiple dimming zones, forming multiple exposure beams emitted from multiple light-transmitting areas, thereby exposing multiple points on the photosensitive drum. This reduces the number of times the dimming panel needs to switch between on and off, and reduces the difficulty of controlling the light source assembly. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic diagram of the overall structure of a printing device provided in an exemplary embodiment of the present application;
[0017] Figure 2 is a cross-sectional structural diagram of a light source assembly and a collimating lens provided in an exemplary embodiment of the present application;
[0018] Figure 3 is a schematic diagram of multiple dimming zones of a dimming panel provided in an exemplary embodiment of the present application;
[0019] Figure 4 2 is another schematic diagram of multiple dimming zones of a dimming panel provided in an exemplary embodiment of the present application.
[0020] Description of reference numerals:
[0021] 100. Printing device;
[0022] 11. Light source assembly; 111. Dimming panel; TA, dimming zone; 112. Liquid crystal assembly; 1121. Liquid crystal molecules; 1122. First substrate; 1123. Second substrate; 1124. Sealing glue; 1125. First electrode; 1126. Second electrode; 1127. First polarizer; 1128. Second polarizer; 1129. Light shielding layer; 1130. Light-transmitting opening; 1131. Light shielding portion; 114. Backlight source;
[0023] 12. Photosensitive drum;
[0024] 13. Charging roller;
[0025] 14. Conveying assembly; 141. Conveying roller;
[0026] 15. Developing assembly; 151. Developing roller; 152. Toner supply box;
[0027] 16. Transfer assembly; 161. Transfer roller;
[0028] 17. Fusing assembly; 171. Fusing roller;
[0029] 18. Collimating lens; 181. Light incident surface;
[0030] 20. Print substrate. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.
[0032] Figure 1 Schematic diagram of the overall structure of the printing device provided in an exemplary embodiment of the present application. Figure 2 2 is a cross-sectional structural diagram of a light source assembly and a collimating lens provided in an exemplary embodiment of the present application.
[0033] See also Figure 1 The printing device 100 includes a light source assembly 11 , a photosensitive drum 12 , a conveying assembly 14 , a developing assembly 15 , a transfer assembly 16 and a fixing assembly 17 .
[0034] The photoconductive drum 12 is positioned below the light source assembly 11. The surface of the photoconductive drum 12 is configured to form a charge layer, such as a negative charge layer. A photoconductive material is disposed on the surface of the photoconductive drum 12, which changes its conductivity when exposed to light. Examples of photoconductive materials include, but are not limited to, selenium, silicon, or organic photoconductive materials.
[0035] In some embodiments, as Figure 1 As shown, the printing device 100 may further include a charged charging roller 13, the rotation direction of which is opposite to the rotation direction of the photosensitive drum 12, and the charging roller 13 is in direct contact with the photosensitive drum 12. The charged charging roller 13 can transfer electric charge to the surface of the photosensitive drum 12 to form a charge layer on the surface of the photosensitive drum 12.
[0036] The light source assembly 11 is configured to generate an exposure beam that exposes the charge layer on the photosensitive drum 12. Because photoconductive materials change their conductivity when exposed to light, the charge layer on some areas of the photosensitive drum 12 is lost upon exposure, leaving areas with no charge or a charge of opposite electrical properties. The charge layer in the unexposed areas and the charge distribution in the exposed areas together form a charged shadow.
[0037] The transport assembly 14 transports the printing substrate 20 between the transfer assembly 16 and the photosensitive drum 12. In some embodiments, as shown in FIG. Figure 1 As shown, the conveying assembly 14 includes two conveying rollers 141 , which rotate in opposite directions. The printing substrate 20 is located between the two conveying rollers 141 .
[0038] The developing assembly 15 is located on one side of the photosensitive drum 12. For example, on the right side of the photosensitive drum 12. The developing assembly 15 is configured to transport toner to the surface of the photosensitive drum 12 so that the toner is affected by the charged latent image and forms a toner pattern on the surface of the photosensitive drum 12. In some embodiments, the developing assembly 15 may include one or more developing rollers 151 and one or more toner supply boxes 152. The toner supply box 152 contains toner. One developing roller 151 is located in one toner supply box 152 and contacts the photosensitive drum 12. The direction of rotation of the developing roller 151 is opposite to the direction of rotation of the photosensitive drum 12. If black and white printing is to be achieved, a toner supply box 152 containing black toner is provided. If color printing is to be achieved, a plurality of toner supply boxes 152 containing toners of a plurality of different colors are provided, and each toner supply box 152 contains toner of one color.
[0039] The transfer assembly 16 is located after the transport assembly 14 in the path of the printing substrate 20. Furthermore, the transfer assembly 16 is located below the photosensitive drum 12. The transfer assembly 16 is configured to bring the printing substrate 20 into contact with the photosensitive drum 12 to transfer the toner image onto the printing substrate 20. In some embodiments, the transfer assembly 16 includes a transfer roller 161 that rotates in a direction opposite to that of the photosensitive drum 12. The printing substrate 20 is located between the transfer roller 161 and the photosensitive drum 12. The transfer roller 161 applies a force to the printing substrate 20, forcing the printing substrate 20 into contact with the photosensitive drum 12, thereby transferring the toner image onto the printing substrate 20.
[0040] The fixing assembly 17 is located after the transfer assembly 16 in the path of the printing substrate 20. The fixing assembly 17 is configured to heat the printing substrate 20 to form a print pattern on the printing substrate 20. In some embodiments, the fixing assembly 17 includes two fixing rollers 171 rotating in opposite directions. The printing substrate 20 is located between the two fixing rollers 171. The two fixing rollers 171 heat and pressurize the printing substrate 20, causing the toner to penetrate into the printing substrate 20 to form a printed image.
[0041] In some embodiments, as Figure 2 As shown, the light source assembly 11 includes a dimming panel 111 and a backlight source 114. The dimming panel 111 is located on the light-emitting side of the backlight source 114 and has a plurality of dimming areas TA. The backlight source 114 is configured to emit backlight to the inside of the dimming panel 111. The dimming panel 111 is configured to control the transmittance of the backlight in each dimming area TA based on the image data to form an exposure light beam. Compared with the problem that the laser print head can only scan one point at a time, resulting in the need for high-frequency switching, the dimming panel 111 of the embodiment of the present application can control the transmittance of the backlight passing through multiple dimming areas TA at one time to form multiple exposure light beams emitted from multiple dimming areas TA, thereby exposing multiple points on the photosensitive drum 12. In this way, the number of times the dimming panel 111 switches between on and off can be reduced, reducing the difficulty of controlling the light source assembly 11.
[0042] In some embodiments, the backlight source 114 may include a white light source. In some embodiments, the backlight source 114 may also include a monochromatic light source, such as any one of a red light source, a green light source, and a blue light source. In some embodiments, the backlight source 114 may also include a white light source, a red light source, a green light source, and a blue light source. The backlight source 114 may include an edge-lit backlight module or a direct-lit backlight module.
[0043] In some embodiments, the dimming panel 111 includes a liquid crystal component 112. The liquid crystal component 112 includes a plurality of liquid crystal molecules 1121. Thus, the rotation characteristics of the plurality of liquid crystal molecules 1121 under an electric field can be utilized to control the transmittance of the dimming area TA, thereby controlling the number and intensity of exposure light beams emitted from the dimming panel 111.
[0044] In some embodiments, the response time of the liquid crystal molecules 1121 can be less than or equal to 500 μs, thereby shortening the response time of the liquid crystal molecules 1121. This shortens the time it takes for the dimming panel 111 to regulate the transmittance of the backlight, allowing the dimming panel 111 to emit an exposure light beam more quickly to expose the charge layer on the photosensitive drum 12, shortening the exposure time and increasing the printer's printing speed. Optionally, the response time of the liquid crystal molecules 1121 is less than or equal to 300 μs, or less than or equal to 200 μs.
[0045] In some embodiments, the liquid crystal molecules 1121 include ferroelectric liquid crystal materials. Due to the spontaneous polarization, high dielectric constant, small molecular structure, and low viscosity of ferroelectric liquid crystal materials, their response time is approximately 100 μs, thereby improving the response speed of the liquid crystal molecules 1121.
[0046] In some embodiments, the liquid crystal assembly 112 includes a first substrate 1122, a second substrate 1123, a sealing sealant 1124, a plurality of first electrodes 1125, and a second electrode 1126. The sealing sealant 1124 is located between the first substrate 1122 and the second substrate 1123, bonding the first substrate 1122 and the second substrate 1123. The plurality of first electrodes 1125 and the second electrodes 1126 are located between the first substrate 1122 and the second substrate 1123. A first voltage is applied to the first electrodes 1125, and a second voltage is applied to the second electrodes 1126, creating a voltage difference between the first and second voltages. The electric field generated by the voltage difference acts on the plurality of liquid crystal molecules 1121, causing the liquid crystal molecules 1121 to rotate, thereby controlling the transmittance of the backlight. In some embodiments, the plurality of first electrodes 1125 and the second electrodes 1126 can be located on either the first substrate 1122 or the second substrate 1123. In some embodiments, a plurality of first electrodes 1125 may be located on the first substrate 1122 , and the second electrodes 1126 may be located on the second substrate 1123 .
[0047] In some embodiments, the liquid crystal assembly 112 further includes a first polarizer 1127 and a second polarizer 1128 .
[0048] The first substrate 1122 and the second substrate 1123 are located between the first polarizer 1127 and the second polarizer 1128 .
[0049] The polarization direction of the first polarizer 1127 is perpendicular to the polarization direction of the second polarizer 1128 .
[0050] In some embodiments, the liquid crystal assembly 112 further includes a processor (not shown) that receives image data to be printed and modulates the image data into a first voltage of the first electrode 1125. The first voltage is regulated so that the difference between the first voltage and the second voltage is adjusted to adjust the transmittance of the dimming area TA.
[0051] In some embodiments, the liquid crystal assembly 112 does not include a color filter layer, thereby improving the problem of reduced backlight intensity caused by the color filter layer absorbing backlight, increasing the brightness of the exposure light beam emitted from the dimming area TA, and thereby improving the exposure effect of the exposure light beam on the charge layer. The color filter layer may include red, blue, and green color resists that can filter light.
[0052] In some embodiments, the dimming panel 111 further includes a light shielding layer 1129, which includes a light-transmitting opening 1130 and a light-shielding portion 1131. The light-shielding portion 1131 overlaps with the gap between adjacent dimming areas TA, and the light-transmitting opening 1130 overlaps with the dimming area TA. The light-transmitting opening 1130 ensures that the backlight is emitted from each dimming area TA, and the light-shielding portion 1131 reduces the risk of crosstalk between light emitted from adjacent dimming areas TA. In some embodiments, the light shielding layer 1129 can be disposed on a substrate with the second electrode 1126, for example, the light shielding layer 1129 and the second electrode 1126 are both disposed on the second substrate 1123. In some embodiments, the light shielding layer 1129 can include a black matrix, and the black matrix includes a light-transmitting opening 1130.
[0053] In some embodiments, the printing device 100 further includes a collimating lens 18, which is located on the light-emitting side of the light source assembly 11 and is arranged corresponding to the dimming area TA. In this way, the collimating lens 18 collimates the exposure light beam emitted from the dimming area TA, reduces the problem of mutual crosstalk between the exposure light beams emitted from adjacent dimming areas TA, and improves the problem of exposure error caused by mutual crosstalk between exposure light beams, which in turn causes blurred printing. In some embodiments, a collimating lens 18 is provided on the light-emitting side of each dimming area TA of the dimming panel 111 to collimate the light emitted from each dimming area TA. In some embodiments, a plurality of collimating lenses 18 can be provided on the light-emitting surface of the dimming panel 111, or on an independent light-transmitting substrate, which is located on the light-emitting side of the dimming panel 111.
[0054] In some embodiments, the collimating lens 18 may include a self-focusing lens that smoothly and continuously converges the exposure light beam emitted from the dimming area TA to a point. The self-focusing lens is a cylindrical optical lens with a radially gradient refractive index distribution and has a focusing function.
[0055] In some embodiments, the collimating lens 18 has a light incident surface 181, and the shape of the light-transmitting opening 1130 is the same as the shape of the light incident surface 181. This allows more exposure light beams emitted from each light-transmitting opening 1130 to enter the collimating lens 18 through the corresponding light incident surface 181, thereby reducing crosstalk between exposure light beams emitted from adjacent dimming areas TA, improving exposure accuracy, and thereby enhancing the clarity of the printed image. In some embodiments, the shape of the light-transmitting opening 1130 may include, but is not limited to, one or more of a circle, a rectangle, an ellipse, and a triangle.
[0056] In some embodiments, a working cycle of the light source assembly 11 includes a liquid crystal response period of the liquid crystal assembly 112 and a light-emitting period of the backlight source 114. In a working cycle, the light-emitting period is later than at least part of the liquid crystal response period. Thus, in a working cycle, the backlight source 114 is turned on at least after the liquid crystal is deflected for a period of time, shortening the light-emitting time of the backlight source 114, reducing the driving power consumption of the backlight source 114, and thereby reducing the power consumption of the light source assembly 11. In some embodiments, the entire light-emitting period of the backlight source 114 is after the liquid crystal response period of the liquid crystal assembly 112, so that the backlight source 114 is turned on after the liquid crystal is reversed to the target state, shortening the turn-on time of the backlight source 114, and thereby reducing the power consumption of the light source assembly 11.
[0057] In some embodiments, the time corresponding to the liquid crystal response period and the light emitting period is less than or equal to the period of one working cycle, so as to increase the speed of generating the exposure light beam, which is beneficial to improving the overall printing speed of the printing device 100.
[0058] In some embodiments, the light-emitting period may be 10 to 40 μs. In some embodiments, the liquid crystal response period may be less than or equal to 140 μs. In some embodiments, a duty cycle may be less than or equal to 180 μs to increase exposure speed and printing speed.
[0059] Figure 3 Schematic diagram of multiple dimming zones of a dimming panel provided in an exemplary embodiment of the present application. Figure 4 2 is another schematic diagram of multiple dimming zones of a dimming panel provided in an exemplary embodiment of the present application.
[0060] In some embodiments, as Figure 3 and Figure 4As shown, the dimming panel 111 may be provided with one or more rows of dimming areas TA. A row of dimming areas TA includes multiple dimming areas TA arranged along a first direction X, with gaps between adjacent dimming areas TA. When the dimming panel 111 is provided with multiple rows of dimming areas TA, the multiple rows of dimming areas TA are arranged along a second direction Y, which is aligned with the first direction X. In some embodiments, the first direction X may be the length direction of the dimming panel 111, and the second direction Y may be the width direction of the dimming panel 111.
[0061] In some embodiments, as Figure 3 As shown, when the dimming panel 111 is provided with a row of dimming areas TA, the transmittance of each dimming area TA to backlight can be adjusted simultaneously to achieve exposure of a row of charges in the charge layer. This improves exposure efficiency and reduces the difficulty of controlling the dimming panel 111 between on and off.
[0062] In some embodiments, as Figure 4 As shown, when the dimming panel 111 is provided with multiple rows of dimming areas TA, the transmittance of each of at least two rows of dimming areas TA to backlight can be adjusted simultaneously to achieve exposure of at least two rows of charges in the charge layer. This improves exposure efficiency and reduces the difficulty of controlling the dimming panel 111 between on and off.
[0063] The description of the above embodiments is only used to help understand the technical solutions and core ideas of this application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A printing device, characterized in that: include: A light source assembly comprising a dimming panel and a backlight source; the dimming panel is located on the light-emitting side of the backlight source and has a plurality of dimming zones; the backlight source is configured to emit backlight into the interior of the dimming panel; the dimming panel is configured to control the transmittance of the backlight in each of the dimming zones based on image data to form an exposure beam; The photosensitive drum is located below the light source assembly. The surface of the photosensitive drum is configured to form a charge layer. After the charge layer is exposed by the exposure light beam, the surface loses the charge of the exposed area to form a charged latent image on the surface.
2. The printing device according to claim 1, wherein The dimming panel includes a liquid crystal component, and the liquid crystal component includes a plurality of liquid crystal molecules.
3. The printing device according to claim 2, wherein: The response time of the liquid crystal molecules is less than or equal to 500 μs.
4. The printing device according to claim 3, characterized in that The plurality of liquid crystal molecules include ferroelectric liquid crystal material.
5. The printing device according to claim 2, wherein: The liquid crystal assembly does not include a color filter layer.
6. The printing device according to claim 2, wherein: One working cycle of the light source assembly includes a liquid crystal response period of the liquid crystal assembly and a light emitting period of the backlight source; In one of the working cycles, the light emitting period is later than at least a portion of the liquid crystal response period.
7. The printing device according to any one of claims 1 to 6, characterized in that: The printing device further includes a collimating lens, which is located on the light-emitting side of the light source assembly and is arranged corresponding to the dimming zone.
8. The printing device according to claim 7, wherein: The dimming panel further includes a light shielding layer, which includes a light-transmitting opening and a light-shielding portion. The light-shielding portion overlaps with a gap between adjacent dimming areas, and the light-transmitting opening overlaps with the dimming area.
9. The printing device according to claim 8, characterized in that The collimating lens has a light incident surface, and the shape of the light-transmitting opening is the same as that of the light incident surface.
10. The printing device according to any one of claims 1 to 6, characterized in that Also includes: a developing assembly configured to transport toner to the surface of the photosensitive drum so that the toner is acted upon by the charged latent image to form a toner pattern on the surface of the photosensitive drum; a transfer assembly configured to bring a printing substrate into contact with the photosensitive drum to transfer the toner image onto the printing substrate; as well as The fixing assembly is configured to heat the printing substrate so that the toner image forms a printing pattern on the printing substrate.