Uniform surface light source

Abstract

The utility model provides a uniform area light source. The uniform area light source comprises a shell, a lamp panel, a uniform light plate, a temperature control platform, a light source driving module and a control module, a lamp panel and a temperature control platform are arranged in the shell, the lamp panel comprises a printed circuit board and a plurality of LED lamp beads which are fixed to the printed circuit board and electrically connected with the printed circuit board, and a light mixing cavity is jointly formed among the light uniformizing plate, the lamp panel and the shell; the temperature control platform is in contact with the lamp panel and is arranged on the other side of the LED lamp beads on the lamp panel; the light source driving module is electrically connected with the lamp panel and supplies power to the LED lamp beads; the control module is electrically connected with the light source driving module and controls output adjustment of the light source driving module. The utility model aims to solve the problems of large volume, non-uniform light color of a light-emitting surface and poor long-term / short-term stability of the existing uniform surface light source, and meets the requirements of metering and testing purposes.

Description

TECHNICAL FIELD

[0001] The utility model relates to light source technical field, concretely relates to a uniform area light source for measurement and test. BACKGROUND

[0002] The area light source with uniform and stable light emission can be used as a standard or reference calibration in optical radiation measurement, and in some image test occasions, a uniform area light source is also needed to provide uniform and stable backlight, and the former has higher requirement for the uniform light surface. Traditionally, for measurement and calibration and value transmission, an integrating sphere is generally used to realize the uniform area light source, however, the technical scheme has two obvious defects, one is that the volume is relatively large, when the sample loading space of the calibrated instrument is relatively small, the requirement cannot be met, and the other is that due to the light mixing and attenuation of the integrating sphere, the light output is relatively low, and the integrating sphere can only be used for brightness calibration, and cannot realize the value transmission of luminous intensity. Another area light source realized based on LED and light homogenizing plate can realize relatively high brightness, but due to the limitation of the design structure and heat dissipation material, the LED area light source is prone to light output drift and color change caused by uneven heat dissipation in the working process, and the uniformity of the area light source is not ideal, and it is difficult to meet the high requirement of measurement and calibration. SUMMARY

[0003] In view of the defects of the prior art, the utility model provides an area light source, which aims to solve the problems of large volume, non-uniform light color of the emitting surface, and poor long-term / short-term stability of the prior art area light source, and meets the requirement of measurement and test.

[0004] To achieve the above technical purpose, the utility model adopts the following technical scheme:

[0005] The utility model provides an area light source, which comprises a shell, a lamp plate, a light homogenizing plate, a temperature control platform, a light source driving module and a control module, the shell is provided with the lamp plate and the temperature control platform, the lamp plate comprises a printed circuit board and a plurality of LED lamp beads fixed on the printed circuit board and electrically connected with the printed circuit board, the light homogenizing plate, the lamp plate and the shell jointly form a light mixing cavity, the temperature control platform is in contact with the lamp plate and is arranged on the other side of the LED lamp beads on the lamp plate, the light source driving module is electrically connected with the lamp plate and supplies power for the LED lamp beads, and the control module is electrically connected with the light source driving module and controls the output adjustment of the light source driving module.

[0006] In the above technical solution, the shell serves as a support and protection structure of the entire uniform area light source, can effectively fix the lamp panel, the light uniformity plate and the temperature control platform, and prevent external dust and moisture from entering. The printed circuit board is generally made of a material with high thermal conductivity and high insulation performance to ensure stable transmission of current and safe operation of the LED lamp beads. The LED lamp beads can be uniformly distributed on the printed circuit board according to a specific arrangement, and the large-area and uniform illumination effect can be achieved through the light mixing cavity.

[0007] The light emitted by the LED lamp beads can be fully mixed and uniformly distributed in the light mixing cavity, and the light uniformity of the uniform area light source is improved. The light uniformity plate is generally made of a material with high diffusivity and high transmittance (for example, PMMA material), which further improves the uniformity of the light. Preferably, the side wall of the shell is coated with a high-reflectivity material, or the side wall of the shell is made of a high-reflectivity material.

[0008] The light source driving module is electrically connected with the lamp panel and is responsible for providing stable power supply for the lamp panel. The control module is electrically connected with the light source driving module and can realize flexible and intelligent adjustment of the luminous intensity, brightness, color temperature and other parameters of the uniform area light source under the control of the control module, so as to meet the needs of different application scenarios. The light source driving module generally adopts a constant current driving mode, and as a technical solution, the LED junction voltage is measured to indirectly monitor the LED junction temperature, so as to ensure that the LED lamp beads remain in a stable working state. The temperature control platform is in contact with the lamp panel and can maintain a constant temperature or adjust the temperature within a certain range. The light source driving module can be arranged inside the shell or externally.

[0009] As a technical solution, the temperature control platform further comprises a temperature control circuit, the temperature control circuit is electrically connected with the temperature control platform, and the temperature control circuit is electrically connected with the control module. Under the action of the temperature control circuit, the temperature control platform realizes heating or refrigeration power adjustment. The temperature control platform generally comprises a heating module or a refrigeration module, and the temperature control circuit is electrically connected with the heating module or the refrigeration module. The heating module generally adopts a resistance heating mode, including heating elements such as electric heating wires and ceramic PTC heating sheets, and the heating power is adjusted by controlling the size of the current to achieve the required temperature; and the refrigeration module generally adopts a semiconductor refrigeration technology.

[0010] As a technical solution, the temperature control platform is connected with the LED junction voltage measurement. When the junction voltage rises, it means that the junction temperature decreases. Then the junction voltage is reduced by reducing the refrigeration of the temperature control platform or heating the temperature control platform to make the LED junction temperature rise. Conversely, when the junction voltage decreases, it means that the LED lamp bead junction temperature rises. Then the junction temperature of the LED lamp bead is reduced by the cooling method of the temperature control platform. Specifically, it also includes a junction voltage measurement module, which is electrically connected with the printed circuit board to collect the forward voltage of the LED lamp bead. The junction voltage measurement module is electrically connected with the control module, and the control module controls the output of the temperature control circuit or the light source driving module according to the measurement result of the junction voltage measurement module. The junction voltage of the LED lamp bead is measured to indirectly monitor the junction temperature of the LED lamp bead, so as to ensure that the LED lamp bead maintains a stable working state. In a specific embodiment, the light source driving module passes a constant current to the LED lamp bead on the lamp panel. The junction voltage measurement module measures the junction voltage of the LED lamp bead and feeds back the measured result to the temperature control circuit of the temperature control platform through the control module. For example, when the junction voltage rises, the temperature control circuit heats the temperature control platform to make the junction temperature of the LED lamp bead rise. The junction voltage measurement module measures the junction voltage of the LED lamp bead again and feeds back. After multiple feedback and adjustment of the junction voltage measurement module and the temperature control platform, the junction voltage of the LED lamp bead on the lamp panel tends to be stable, that is, the junction temperature of the LED lamp bead tends to be stable. At this time, a uniform and stable uniform area light source is obtained.

[0011] As a technical solution, it also includes one or more monitoring optical detectors, which are arranged in the housing and located on the inner side of the light homogenizing plate. The monitoring optical detector can be a photocell or a spectrometer. The photocell is used to monitor the luminous intensity of the uniform area light source in real time, and the spectrometer is used to monitor the spectral information of the output light of the uniform area light source in real time. The monitoring optical detector is electrically connected with the control module, and the control module controls the output of the temperature control circuit or the light source driving module according to the measurement result of the monitoring optical detector. For example, the monitoring optical detector feeds back the measured luminous intensity information to the control module. When the light intensity deviates from the preset value, the control module controls the output power of the light source driving module to realize the automatic adjustment of the luminous intensity.

[0012] The prior art generally directly adjusts all LED lamp beads through a single drive circuit. When the output power is greatly reduced or increased, the working current and voltage of the LED lamp beads will change greatly, which may cause the spectral characteristics to deviate. As a technical solution, the light source drive module includes two or more independent drive circuits; each drive circuit is electrically connected to a string of LED lamp beads; and the LED lamp bead strings are arranged at intervals on the lamp panel. In this technical solution, since each drive circuit is independent, the LED lamp bead string connected thereto can realize independent switching and dimming. Specifically, to achieve a relatively large range of brightness adjustment, if the overall current adjustment mode is used, the color temperature of the LED will be significantly different in the low current region and the high current region. However, using the combination of the multiple independent drive circuits and the LED lamp bead strings can achieve simple and efficient adjustment while ensuring the spectrum unchanged. For example, three LED lamp bead strings with the same light output can be set to low power when only the first string is lit, medium power when the first and second strings are lit, and high power when all three strings are lit. This technical solution avoids the spectral deviation phenomenon caused by excessive adjustment of the LED lamp beads, thereby ensuring the uniformity and stability of the light in terms of brightness and color.

[0013] The technical solution of the above two or more drive circuits can be realized in the following ways: one is that the light source drive module includes two or more independent drive power supplies, each drive power supply is connected to one or more independent drive circuits, and the independent working of each string of LED lamp beads is realized by adjusting each drive power supply; two is that the light source drive module includes one drive power supply, the drive power supply is connected to two or more independent drive circuits, and the two drive circuits are connected in parallel to the drive power supply. The switching or current adjustment of the drive circuit can be realized by means of series resistance or switch, etc. The above two ways can be combined to realize independent control of the multiple drive circuits.

[0014] As a technical solution, two or more different types of LED lamp beads are included, the different types include different powers and different spectra; at least one LED lamp bead string has the two or more different LED lamp beads and the different types of LED lamp beads are arranged at intervals, or each string of LED lamp beads has the same type of LED lamp bead and the types of LED lamp beads of at least two strings of LED lamp beads are different. A string of LED lamp beads includes two or more LED lamp beads, and the different LED lamp beads are arranged at intervals. This arrangement is suitable for cases where the output spectrum consistency is required to be relatively high and fixed. The same string of LED lamp beads can also be a uniform type of LED lamp bead, and the powers or spectra of different strings are different.

[0015] As a technical solution, the two or more different types of LED lamp beads at least include: a combination of blue light LED lamp beads and low color temperature white light LED lamp beads, or a combination of high color temperature white light LED lamp beads and low color temperature white light LED lamp beads, or a combination of white light LED lamp beads and infrared LED lamp beads, or a combination of white light LED lamp beads and ultraviolet LED lamp beads. For example, a plurality of white light LED lamp bead strings with different color temperatures can be arranged, and the white light LED lamp bead strings with different color temperatures are arranged together in an interval to realize flexible color temperature adjustment function; the white light LED lamp bead string and one or more monochromatic light (such as red, green, blue, etc.) LED lamp bead string can be integrated on the lamp panel, and the light output is adjusted by adjusting the current of different strings, so as to achieve the expected color temperature.

[0016] In a specific embodiment, the same type of LED lamp bead string is uniformly arranged on the lamp panel, which includes a blue light LED lamp bead string and a low color temperature white light LED lamp bead (the correlated color temperature is about 2900K). The blue light LED lamp bead string and the low color temperature white light LED lamp bead string are arranged in an interval, and the light output of the two strings of LED is adjusted and controlled by two different light source driving modules, so as to realize the adjustment of the light intensity and the color temperature. As a preferred, the light output is adjusted by the light source driving module control, and the uniform light output with a correlated color temperature of 4103K is realized, and the light source is matched with the relative spectral power distribution of CIE reference light source L41.

[0017] In another specific embodiment, the same type of LED lamp bead string is uniformly arranged on the lamp panel, and the high color temperature white light LED lamp bead (the correlated color temperature is about 5700K) and the low color temperature white light LED lamp bead (the correlated color temperature is about 2700K) are included in a string of LED lamp beads. The high color temperature white light LED lamp bead and the low color temperature white light LED lamp bead are arranged in an interval on the lamp panel, and the stable adjustment of the output light color temperature and the spectral power distribution can be realized by the light source driving module control.

[0018] As a technical solution, in the spatial arrangement on the lamp panel, the two or more different spectral power distribution LED lamp beads are arranged in pairs and adjacent to each other, and each pair of LED lamp beads is separated from other pairs by a distance, so as to improve the surface color uniformity of the surface light source.

[0019] As a technical solution, the LED lamp beads in different LED lamp bead strings are arranged at intervals on the lamp panel so that each LED lamp bead is adjacent to the position of the LED lamp bead in other LED lamp bead string; or the LED lamp bead strings of different strings are arranged at intervals on the lamp panel. As a preferred, any two adjacent LED lamp beads belong to different LED lamp bead strings. The LED lamp beads in each LED lamp bead string are arranged at intervals, which can more effectively balance the temperature of the lamp beads in different LED lamp bead strings, avoid the temperature concentration in the area where the LED lamp bead string with large current and more heat is located, thereby reducing the risk of reducing the service life of the lamp bead caused by the temperature being too high due to the pressure difference, and improving the product reliability. In addition, by controlling a string of LED lamp beads as a channel, the cost of the control circuit can be reduced.

[0020] As a technical solution, the lamp panel includes blue light LED lamp beads and low color temperature white light LED lamp beads, and the blue light LED lamp beads are arranged adjacent to the low color temperature white light LED lamp beads; the light output is adjusted by the light source driving module to realize the uniform light output matched with the relative spectral power distribution of the CIE reference light source L41.

[0021] In a specific embodiment, the lamp panel includes blue light LED lamp bead strings and low color temperature white light LED lamp bead strings; the LED lamp beads in different LED lamp bead strings are arranged at intervals so that the blue light LED lamp beads are adjacent to the positions of the low color temperature white light LED lamp beads, or the blue light LED lamp bead strings and the low color temperature white light LED lamp bead strings are arranged at intervals on the lamp panel; the light output is adjusted by the light source driving module to realize the uniform light output matched with the relative spectral power distribution of the CIE reference light source L41.

[0022] In another specific embodiment, the lamp panel includes high color temperature white light LED lamp bead strings and low color temperature white light LED lamp bead strings; the LED lamp beads in different LED lamp bead strings are arranged at intervals so that the high color temperature white light LED lamp beads are adjacent to the positions of the low color temperature white light LED lamp beads, or the high color temperature white light LED lamp bead strings and the low color temperature white light LED lamp bead strings are arranged at intervals on the lamp panel; the light output is adjusted by the light source driving module to realize the uniform light output matched with the relative spectral power distribution of the CIE reference light source L41.

[0023] As a technical solution, only one LED lamp bead is included, and the LED lamp beads of each LED lamp bead string are uniformly arranged. For example, when we expect to output light of a specific color temperature (such as 4100 K), the same type of lamp bead (such as a white light LED lamp bead with a correlated color temperature of about 4100 K) is used to ensure that each lamp bead contributes stable and consistent spectral components to the light of the color temperature, which is easier to control and manage. Further, in order to achieve a larger output intensity variation range, a multi-string LED lamp bead string cooperation mode can be used, and the lighting state of the LED lamp bead string can be controlled by each driving circuit, so that flexible adjustment from low intensity to high intensity can be realized while the spectral characteristics (such as 4100 K) are basically unchanged. Different LED lamp bead strings can be independently or combined to be switched on or dimmed, thereby meeting different needs for light intensity in different scenarios.

[0024] As a technical solution, the housing further includes a limiting diaphragm, which is arranged on the front side of the light homogenizing plate (the side of the light homogenizing plate away from the lamp plate). Preferably, the limiting diaphragm for limiting the light source output surface is an adjustable diaphragm, which adjusts the size of the light source output surface by adjusting the aperture of the limiting diaphragm, effectively solving the problem of uneven illumination effect and uneven illumination brightness that may occur in the light source composed of multiple LED lamp beads. In addition, the brightness of the light beam can be adjusted to a certain extent, achieving more uniform and stable illumination effect.

[0025] As a technical solution, the printed circuit board is made of high thermal conductivity material, and the printed circuit board is bonded to the temperature control platform by thermal conductive adhesive. The thermal conductive adhesive has good thermal conductivity, which can quickly conduct the heat on the printed circuit board to the temperature control platform, avoid local overheating, and improve the heat dissipation efficiency.

[0026] As a technical solution, a temperature sensing module is further included, the sensor of the temperature sensing module is in contact with the lamp plate or the temperature control platform, and the temperature sensing module is electrically connected with the control module. The temperature sensing module is used to monitor the temperature of the temperature control platform or the lamp plate in real time, and feed back the information to the control module. Under the control of the control module, the temperature adjusting circuit can maintain the temperature of the temperature control platform (or the temperature of the lamp plate) constant within the set range by adjusting the heating or refrigeration power according to the feedback temperature information. Due to the stability of the LED lamp bead itself, changes in voltage or frequency, local humidity or other environmental conditions will have a significant impact on the output characteristics of the LED lamp bead. Therefore, by setting the temperature sensing module, the sensor of the temperature sensing module is in contact with the lamp plate, and the correlation between the junction voltage and the junction temperature of the LED lamp bead is used to control the working temperature of the LED lamp bead. It should be noted that the temperature sensing module can also be used to compensate and adjust the influence of the change of environmental conditions on the junction temperature of the LED lamp bead.

[0027] As a technical scheme, the light guide plate is arranged in parallel with the light homogenizing plate, and the light emitting surface of the LED lamp bead is arranged perpendicularly to the light guide plate. In a specific embodiment, the uniform area light source adopts a side light emitting form, the lamp beads of the lamp plate are arranged around the side of the light guide plate, the light beams emitted by the lamp beads enter the light guide plate perpendicularly, and the light beams are uniformly emitted after multiple reflection and refraction in the light guide plate, so that the uniform distribution of light is further realized, light loss is reduced, and light efficiency is improved.

[0028] The utility model discloses a uniform area light source, through the different arrangement mode of LED lamp bead, utilize light source drive module to realize the flexible intelligent adjustment of the luminous intensity, brightness, color temperature etc. of uniform area light source, through the design of light homogenizing plate, temperature control platform, junction voltage measurement module and temperature sensing control module etc., ensure that LED lamp bead stable work, improve the life, have small volume, luminous surface light color even, long-term / short-term performance stability simultaneously, can satisfy the demand of different purposes such as measurement test. BRIEF DESCRIPTION OF DRAWINGS

[0029] BRIEF DESCRIPTION OF DRAWINGS Figure 1 It is the structural schematic diagram of uniform area light source in example 1;

[0030] BRIEF DESCRIPTION OF DRAWINGS Figure 2 It is the arrangement schematic diagram of lamp bead in example 1;

[0031] BRIEF DESCRIPTION OF DRAWINGS Figure 3 It is the structural schematic diagram of uniform area light source in example 2;

[0032] BRIEF DESCRIPTION OF DRAWINGS Figure 4 It is the arrangement schematic diagram of lamp bead in example 2;

[0033] BRIEF DESCRIPTION OF DRAWINGS Figure 5 It is the relative spectral power distribution schematic diagram of uniform area light source in example 2;

[0034] BRIEF DESCRIPTION OF DRAWINGS Figure 6 It is the structural schematic diagram of uniform area light source in example 3;

[0035] BRIEF DESCRIPTION OF DRAWINGS Figure 7 And BRIEF DESCRIPTION OF DRAWINGS Figure 8 It is the arrangement schematic diagram of lamp bead in example 3;

[0036] BRIEF DESCRIPTION OF DRAWINGS Figure 9 It is the relative spectral power distribution schematic diagram of uniform area light source in example 3;

[0037] BRIEF DESCRIPTION OF DRAWINGS Figure 10 It is the structural schematic diagram of uniform area light source in example 4;

[0038] BRIEF DESCRIPTION OF DRAWINGS Figure 11 It is the arrangement schematic diagram of lamp bead in example 4;

[0039] BRIEF DESCRIPTION OF DRAWINGS Figure 12This is a schematic diagram of the spatial arrangement of the LED beads on the LED board in Example 4;

[0040] Appendix Figure 13 This is a schematic diagram of the relative spectral power distribution of the uniform surface light source in Example 4;

[0041] Appendix Figure 14 This is a schematic diagram of the uniform surface light source in Example 5;

[0042] Appendix Figure 15 This is a schematic diagram of the LED arrangement in Example 5;

[0043] In the diagram, 1-housing, 2-lamp board, 3-temperature control circuit, 4-light dome, 5-light limiting aperture, 6-temperature control platform, 7-monitoring optical detector, 8-light guide plate, 9-temperature sensing and control module, 10-LED lamp bead, 11-printed circuit board, 12-light source driving module, 13-control module, 14-junction voltage measurement module, 15-driving power supply. Detailed Implementation Example 1

[0044] This embodiment discloses a uniform surface light source, such as Figure 1 As shown, the system includes a housing 1, a lamp board 2, a temperature control circuit 3, a light-diffusing plate 4, a limiting aperture 5, a temperature control platform 6, a light source driving module 12, a control module 13, and a junction voltage measurement module 14. The housing 1 houses the temperature control circuit 3, the light source driving module 12, the control module 13, the junction voltage measurement module 14, the temperature control platform 6, the lamp board 2, the light-diffusing plate 4, and the limiting aperture 5. The light-diffusing plate 4, the lamp board 2, and the housing 1 together form a light mixing cavity. The lamp board 2 includes a printed circuit board 11 and several LED beads 10 fixed on and electrically connected to the printed circuit board 11. The light-diffusing plate 4 is parallel to the lamp board 2 and is located on one side of the lamp board 2; the temperature control platform 6 is in contact with the lamp board 2 and is located on the other side of the LED beads 10 on the lamp board 2; the limiting aperture 5 is located on the outer side of the light-diffusing plate 4. The light source driving module 12 is electrically connected to the lamp board 2 to power the LED beads 10; the control module 13 is electrically connected to the light source driving module 12 to control the output adjustment of the light source driving module 12. The light source driving module 12 includes eight independent driving power supplies 15, each driving power supply 15 is connected to an independent driving circuit, and each driving circuit is electrically connected to a string of LED beads. The LED beads in each string of LED beads are connected in series. The spectral power distribution of the LED beads (10) in each string of LED beads is the same, and the correlated color temperature of the LED beads (10) is about 4000K. The strings of LED beads are evenly spaced on the lamp board 2, such as... Figure 2As shown. Each driving circuit can drive the LED string to emit light independently, allowing for flexible adjustment from low to high intensity while maintaining the spectral characteristics (e.g., 4000 K) essentially unchanged. This embodiment is suitable for situations where the output spectrum consistency requirement is high and relatively fixed, ensuring that each LED contributes a stable and consistent spectral composition to achieve the desired color temperature, making it easier to control and manage. The printed circuit board 11 is made of a high thermal conductivity material and is bonded to the temperature control platform 6 with thermally conductive adhesive. The temperature control platform 6 includes a heating module and a cooling module. The temperature adjustment circuit 3 is electrically connected to the heating and cooling modules in the temperature control platform 6, and is also electrically connected to the control module 13. Under the action of the temperature adjustment circuit 3, the temperature control platform 6 achieves heating or cooling power adjustment. The light source driving module 12 operates in constant current driving mode. The junction voltage measurement module 14 is electrically connected to the printed circuit board 11 to collect the forward voltage of the LED bead 10. The junction voltage measurement module 14 is also electrically connected to the control module 13. The control module 13 controls the output of the temperature control circuit 3 or the light source driving module 12 based on the measurement results from the junction voltage measurement module 14. For example, when the junction voltage increases, it means the junction temperature decreases. Therefore, the junction voltage is reduced by decreasing the cooling of the temperature control platform or by increasing the temperature of the temperature control platform, thus increasing the LED junction temperature. Conversely, when the junction voltage decreases, it means the LED bead junction temperature increases. Therefore, the junction temperature of the LED bead is reduced by cooling the temperature control platform. This feedback adjustment can be achieved under the control of the control module to ensure stable operation of the LED bead. Example 2

[0045] This embodiment discloses a uniform surface light source, such as Figure 3As shown, including the shell 1, lamp plate 2, temperature control circuit 3, light uniformity plate 4, limiting diaphragm 5, temperature control platform 6, monitoring optical detector 7, control module 13, junction voltage measurement module 14, light source driving module 12. The shell 1 is provided with temperature control platform 6, lamp plate 2, light uniformity plate 4, monitoring optical detector 7, junction voltage measurement module 14 and limiting diaphragm 5, temperature control circuit 3, control module 13, light source driving module 12 is externally provided, light uniformity plate 4, lamp plate 2 and shell 1 together form a mixing chamber. The lamp plate 2 includes a printed circuit board 11 and a plurality of LED lamp beads 10 fixed on the printed circuit board 11 and electrically connected with the printed circuit board 11. The temperature control platform 6 is in contact with the lamp plate 2 and is arranged on the other side of the LED lamp bead on the lamp plate; the limiting diaphragm 5 is arranged outside the light uniformity plate 4. The light source driving module 12 is electrically connected with the lamp plate 2 to supply power for the LED lamp beads 10; the control module 13 is electrically connected with the light source driving module 12 to control the output adjustment of the light source driving module 12. The printed circuit board 11 is made of high thermal conductivity material, and the printed circuit board 11 is bonded on the temperature control platform 6 by thermal conductive adhesive. The temperature control platform 6 includes a heating module or a refrigeration module, the temperature control circuit 3 is electrically connected with the heating module or the refrigeration module in the temperature control platform 6, and the temperature control circuit 3 is electrically connected with the control module 13, and the temperature control platform 6 realizes heating or refrigeration power adjustment under the action of the temperature control circuit 3. The light source driving module 12 is in constant current driving mode, the junction voltage measurement module 14 is electrically connected with the printed circuit board 11 to collect the forward voltage of the LED lamp bead 10; the junction voltage measurement module 14 and the control module 13 are electrically connected, and the control module 13 controls the output of the temperature control circuit 3 or the light source driving module 12 according to the measurement result of the junction voltage measurement module 14. The monitoring optical detector 7 is electrically connected with the control module 13, the monitoring optical detector 7 is a photocell, located inside the light uniformity plate 4, used for real-time monitoring the intensity of the uniform area light source output light, and feeding back the measured light intensity information to the control module 13, the control module 13 controls the output of the light source driving module 12 or the temperature control circuit 3, for example, when the light intensity deviates from the preset value, the light source driving module 12 adjusts the output power to realize automatic adjustment of the light intensity.The light source driving module 12 comprises two independent driving power supplies 15, each of which is connected with two independent driving circuits, the two driving circuits are connected in parallel to one driving power supply 15, and the switching adjustment of the driving circuit is realized by switching mode; one driving circuit is electrically connected with one string of LED lamp beads, the LED lamp beads 10 in each string of LED lamp beads are connected in series, the LED lamp beads 10 in each string of LED lamp beads have the same type, and the types of the LED lamp beads 10 in two adjacent strings of LED lamp beads are different, the different types of the LED lamp beads include different powers and different spectrums; the LED lamp bead strings in different strings are arranged in alternate rows on the lamp panel, for example, the first row of LED lamp bead strings comprises high color temperature white light LED lamp beads (the correlated color temperature is about 5700K), the second row of LED lamp bead strings comprises low color temperature white light LED lamp beads (the correlated color temperature is about 2700K), the third row of LED lamp bead strings comprises high color temperature white light LED lamp beads (the correlated color temperature is about 5700K), and the fourth row of LED lamp bead strings comprises low color temperature white light LED lamp beads (the correlated color temperature is about 2700K), as shown in FIG. 1. Figure 4 By arranging the lamp bead strings of different types at intervals, the flexible adjustment of the color temperature and the spectral power distribution can be realized. Specifically, by the control of the light source driving module, the light output with the correlated color temperature of 4100K can be realized, as shown in FIG. 2, and the uniform area light source can be used for the spectral responsivity calibration of the luminometer, and the spectral mismatch error can be effectively reduced. Figure 5 Embodiment three

[0046] The embodiment discloses a uniform area light source, as shown in FIG. 3. Figure 6 ​As shown, it comprises a shell 1, a lamp plate 2, a temperature regulating circuit 3, a light homogenizing plate 4, a limiting diaphragm 5, a temperature control platform 6, a monitoring optical detector 7, a control module 13, a junction voltage measurement module 14, a temperature sensing control module 9 and a light source driving module 12. The temperature control platform 6, the lamp plate 2, the light homogenizing plate 4, the monitoring optical detector 7, the junction voltage measurement module 14, the temperature regulating circuit 3, the control module 13, the light source driving module 12, the temperature sensing control module 9 and the limiting diaphragm 5 are arranged in the shell 1, and the light homogenizing plate 4, the lamp plate 2 and the shell 1 jointly form a light mixing cavity. The limiting diaphragm 5 is arranged outside the light homogenizing plate 4. The lamp plate 2 comprises a printed circuit board 11 and a plurality of LED lamp beads 10 fixed on the printed circuit board 11 and electrically connected with the printed circuit board 11. The light source driving module 12 is electrically connected with the lamp plate 2 to supply power for the LED lamp beads 10; the control module 13 is electrically connected with the light source driving module 12 to control the output adjustment of the light source driving module 12. The printed circuit board 11 is made of high-thermal-conductivity material and is bonded on the temperature control platform 6 through thermal conductive adhesive. The temperature control platform 6 comprises a heating module or a refrigeration module, the temperature regulating circuit 3 is electrically connected with the heating module or the refrigeration module in the temperature control platform 6, and the temperature regulating circuit 3 is electrically connected with the control module 13, so that the temperature control platform 6 realizes heating or refrigeration power adjustment under the action of the temperature regulating circuit 3. The temperature control platform 6 is in contact with the lamp plate 2 and is arranged on the other side of the LED lamp beads 10 on the lamp plate; the sensor of the temperature sensing control module 9 is in contact with the temperature control platform 6, the temperature sensing control module 9 is electrically connected with the control module 13, the temperature sensing control module 9 is used for monitoring the temperature of the temperature control platform 6 in real time and feeding back information to the control module 13, and the temperature regulating circuit 3 can keep the temperature of the temperature control platform (or the temperature of the lamp plate) constant in the set range by adjusting the heating or refrigeration power under the control of the control module 13 according to the feedback temperature information. The monitoring optical detector 7 is electrically connected with the control module 13, the monitoring optical detector 7 is a photoelectric cell and a spectrometer and is respectively arranged on the inside of the light homogenizing plate 4, is used for monitoring the intensity and spectral distribution of the output light of the uniform area light source in real time, and feeds back the measured information to the control module 13, and the control module 13 controls the output of the temperature regulating circuit 3 or the light source driving module 12 according to the measurement result of the junction voltage measurement module 14. The light source driving module 12 is in constant current driving mode, the junction voltage measurement module 14 is electrically connected with the printed circuit board 11 to collect the forward voltage of the LED lamp beads 10, the junction voltage measurement module 14 is electrically connected with the control module 13, the control module 13 controls the output of the temperature regulating circuit 3 or the light source driving module 12 according to the measurement result of the junction voltage measurement module 14 to ensure the stable work of the LED lamp beads.The light source driving module 12 comprises eight independent driving circuits and eight independent driving power supplies 15, each driving power supply 15 is connected with an independent driving circuit; each driving circuit is electrically connected with a string of LED lamp beads, the LED lamp beads 10 in each string of LED lamp beads are connected in series, each string of LED lamp beads has the same type of LED lamp beads 10, and different strings of LED lamp beads (low-color-temperature white LED lamp beads with a relative color temperature of about 2900K and blue LED lamp beads) are arranged at intervals on the printed circuit board 11, and the LED lamp beads in two adjacent strings of LED lamp beads have different power distributions, for example, the blue LED lamp bead string and the low-color-temperature white LED lamp bead string with a relative color temperature of about 2900K are arranged adjacently, as shown in FIG. 1. Figure 7 Alternatively, in the spatial arrangement on the lamp panel, the two different spectral power distribution LED lamp bead strings are arranged in pairs adjacently, each pair of LED lamp bead strings is separated from other pairs by a distance, and one pair of low-color-temperature white LED lamp bead strings with a relative color temperature of about 2900K and blue LED lamp bead strings are separated from another pair of low-color-temperature white LED lamp bead strings with a relative color temperature of about 2900K and blue LED lamp bead strings by a distance, so as to improve the surface color uniformity of the uniform area light source, as shown in FIG. 2. Figure 8 The light output can be adjusted by adjusting the current of different strings of lamp bead strings, so as to achieve the expected color temperature, for example, by controlling the light source driving module, the light output with a relative color temperature of 4103K is achieved, which matches the relative spectral power distribution of the CIE reference light source L41, as shown in FIG. 3. Figure 9 The uniform area light source can be used for photometer spectral responsivity calibration, and effectively reduces the spectral mismatch error. Experiments prove that, compared with the standard A light source, the photometer calibrated by using the uniform area light source further reduces the infrared and ultraviolet response error of the calibration result; when the photometer calibrated by using the light source measures the LED and other commonly used D65 and fluorescent lamps, the spectral mismatch correction factor can be reduced, the measurement accuracy is improved, and the consistency of measurement results between different laboratories is improved. Embodiment Four

[0047] The embodiment discloses a uniform area light source, as shown in FIG. 4. Figure 10As shown, it comprises a shell 1, a lamp panel 2, a temperature regulating circuit 3, a light uniformity panel 4, a limiting diaphragm 5, a temperature control platform 6, a monitoring optical detector 7, a control module 13, a junction voltage measurement module 14, a temperature sensing control module 9 and a light source driving module 12. The temperature control platform 6, the lamp panel 2, the light uniformity panel 4, the monitoring optical detector 7, the junction voltage measurement module 14, the temperature sensing control module 9 and the limiting diaphragm 5 are arranged in the shell 1, and the temperature regulating circuit 3, the control module 13 and the light source driving module 12 are arranged outside. The light uniformity panel 4, the lamp panel 2 and the shell 1 jointly form a mixed light cavity. The limiting diaphragm 5 is arranged outside the light uniformity panel 4. The lamp panel 2 comprises a printed circuit board 11 and a plurality of LED lamp beads 10 fixed on the printed circuit board 11 and electrically connected with the printed circuit board 11. The light source driving module 12 is electrically connected with the lamp panel 2 to supply power for the LED lamp beads 10, and the control module 13 is electrically connected with the light source driving module 12 to control the output adjustment of the light source driving module 12. The light guide plate 8 is arranged in parallel with the light uniformity panel 4, and the light emitting surface of the LED lamp bead 10 is arranged perpendicularly to the light guide plate 8. The printed circuit board 11 is made of high thermal conductivity material and is bonded to the temperature control platform 6 by thermal conductive adhesive. The temperature control platform 6 comprises a heating module or a refrigeration module, the temperature regulating circuit 3 is electrically connected with the heating module or the refrigeration module in the temperature control platform 6, and the temperature regulating circuit 3 is electrically connected with the control module 13, so that the temperature control platform 6 realizes heating or refrigeration power adjustment under the action of the temperature regulating circuit 3. The temperature control platform 6 is in contact with the lamp panel 2 and is arranged on the other side of the LED lamp bead 10 on the lamp panel. The sensor of the temperature sensing control module 9 is in contact with the lamp panel 2 to monitor the temperature of the lamp panel 2 in real time and feed back the information to the control module 13, so that the control module 13 controls the output adjustment of the light source driving module 12 or the temperature regulating circuit 3 to keep the temperature of the temperature control platform (or the temperature of the lamp panel) constant within the set range. The temperature control platform 6 comprises a refrigeration module, the refrigeration module comprises a plurality of heat dissipation fins and a fan, the refrigeration module has a central hole for accommodating the fan, and the heat dissipation fins are distributed outward from the center of the radiator to form an efficient refrigeration structure. The temperature regulating circuit 3 of the temperature control platform is electrically connected with the refrigeration module in the temperature control platform 6, the temperature regulating circuit 3 keeps the temperature of the temperature control platform constant within the set range by adjusting the refrigeration power according to the temperature information fed back by the temperature sensing control module 9. The light source driving module 12 is in constant current driving mode, the junction voltage measurement module 14 is electrically connected with the printed circuit board 11 to collect the forward voltage of the LED lamp bead 10, the junction voltage measurement module 14 is electrically connected with the control module 13, and the control module 13 controls the output of the temperature regulating circuit 3 or the light source driving module 12 according to the measurement result of the junction voltage measurement module 14. The monitoring optical detector 7 is electrically connected with the control module 13, the monitoring optical detector 7 is a photocell and is located inside the light uniformity panel 4 to monitor the light output intensity of the uniform area light source in real time and feed back the measured information to the control module 13, so that the control module 13 controls the output of the temperature regulating circuit 3 or the light source driving module 12 according to the measurement result of the junction voltage measurement module 14.The light source driving module 12 comprises four independent driving power supplies 15, each of which is connected with two independent driving circuits, the two driving circuits are connected in parallel to one driving power supply 15, and the driving circuit is switched by a switch mode; each driving circuit is electrically connected with a string of LED lamp beads, the LED lamp beads 10 in each string of LED lamp beads are connected in series; the LED lamp beads 10 in different strings of LED lamp beads are arranged at intervals on the lamp panel 2 so that each LED lamp bead 10 is adjacent to the LED lamp beads 10 in other strings of LED lamp beads, for example, low color temperature white light LED lamp beads with a relative color temperature of about 2700K and blue light LED lamp beads are staggered, and different strings of LED lamp beads are arranged at intervals, as shown in FIG. 1. Figure 11 In the spatial arrangement on the lamp panel, the low color temperature white light LED lamp beads and the blue light LED lamp beads are arranged in pairs and adjacent to each other, and each pair of LED lamp beads is spaced apart from other pairs by a distance, as shown in FIG. 2. Figure 12 By adjusting the light output, the light output with a correlated color temperature of 4103K can be realized, as shown in FIG. 3. Figure 13 The light source is matched with the relative spectral power distribution of the CIE reference light source L41, and can meet the needs of metrological testing. The embodiment can more effectively balance the temperature of the lamp beads in different strings of LED lamp beads, avoid the situation that the area where the string of LED lamp beads with a large current and a large heat is located is concentrated in temperature, thereby reducing the risk of reduced lamp bead life caused by excessive temperature due to pressure difference, and improving product reliability. Embodiment five

[0048] The embodiment discloses a uniform area light source, which is different from the above-mentioned embodiments in that the embodiment adopts a side light emission mode, as shown in FIG. 4. Figure 14As shown, including the shell 1, lamp plate 2, light uniformity plate 4, limit diaphragm 5, temperature control platform 6, monitoring optical detector 7, light guide plate 8 and light source drive module 12, the shell 1 is equipped with temperature control platform 6, lamp plate 2, light guide plate 8, light uniformity plate 4, monitoring optical detector 7, light source drive module 12 and limit diaphragm 5, the lamp plate 2 includes printed circuit board 11 and a plurality of LED lamp beads 10 fixed on the printed circuit board 11 and electrically connected with the printed circuit board 11, the light guide plate 8 is arranged in parallel with the light uniformity plate 4, the lamp plate 2 is arranged around the light guide plate 8, that is, the four sides of the light guide plate 8 are provided with the lamp plate 2. The monitoring optical detector 7 is a spectrometer, located on the inner side of the light uniformity plate 4, for real-time monitoring of the spectral information of the uniform area light source output light. The temperature control platform 6 is in contact with the lamp plate 2, and is arranged on the other side of the LED lamp bead 10 on the lamp plate 2; the limit diaphragm 5 is arranged on the outer side of the light uniformity plate 4. The light source drive module 12 is electrically connected with the lamp plate 2, and the light source drive module 12 includes two independent drive circuits and two independent drive power supplies, each drive power supply 15 is connected with a drive circuit, each drive circuit is electrically connected with a string of LED lamp beads, and each string of LED lamp beads includes a plurality of LED lamp beads connected in series. The LED lamp beads in different LED lamp bead strings are arranged at intervals on the lamp plate 2, so that each LED lamp bead is adjacent to the LED lamp bead in other LED lamp bead string, for example, low color temperature white light LED lamp beads and high color temperature white light LED lamp beads are staggered, as shown. Figure 15 As shown. The printed circuit board 11 is made of high thermal conductivity material, and the printed circuit board 11 is bonded on the temperature control platform 6 by thermal conductive adhesive. The sensor of the temperature sensing module 9 is in contact with the lamp plate 2, for real-time monitoring of the temperature of the lamp plate, and feeding back information to the control module 13, and the control module 13 controls the output of the light source drive module 12 or the temperature adjusting circuit 3. The temperature control platform 6 includes a heating module, and the temperature adjusting circuit 3 of the temperature control platform is electrically connected with the heating module in the temperature control platform 6. According to the temperature information fed back by the temperature sensing module 9, the temperature adjusting circuit 3 keeps the temperature of the temperature control platform (or the temperature of the lamp plate) constant in the set range by adjusting the heating power. The light source drive module 12 is in constant current drive mode, the junction voltage measurement module 14 is electrically connected with the printed circuit board 11, and the forward voltage of the LED lamp bead 10 is collected. The junction voltage measurement module 14 and the control module 13 are electrically connected, and the control module 13 controls the output of the temperature adjusting circuit 3 or the light source drive module 12 according to the measurement result of the junction voltage measurement module 14, to ensure the stable work of the LED lamp bead.

[0049] The above describes the specific embodiments of the present application in combination with the drawings, but those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present application. Those skilled in the art should understand that the above examples can be modified without departing from the scope and spirit of the present application. The protection scope of the present application is defined by the appended claims.

Claims

1. A uniform area light source, characterized by, The application relates to a light source module, which comprises a shell (1), a lamp plate (2), a light homogenizing plate (4), a temperature control platform (6), a light source driving module (12) and a control module (13); the shell (1) is internally provided with the lamp plate (2) and the temperature control platform (6); the lamp plate (2) comprises a printed circuit board (11) and a plurality of LED lamp beads (10) fixed on the printed circuit board (11) and electrically connected with the printed circuit board (11); the light homogenizing plate (4), the lamp plate (2) and the shell (1) jointly form a light mixing cavity; the temperature control platform (6) is in contact with the lamp plate (2) and is arranged on the other side of the LED lamp beads (10) on the lamp plate (2); the light source driving module (12) is electrically connected with the lamp plate (2) and supplies power for the LED lamp beads (10); the control module (13) is electrically connected with the light source driving module (12) and controls the output adjustment of the light source driving module (12).

2. The uniform area light source of claim 1, wherein, The application further comprises a temperature control circuit (3) of the temperature control platform (6), the temperature control circuit (3) is electrically connected with the temperature control platform (6), and the temperature control circuit (3) is electrically connected with the control module (13); under the action of the temperature control circuit (3), the temperature control platform (6) realizes heating or refrigeration power adjustment.

3. A uniform area light source according to claim 2, characterized in that The application further comprises a junction voltage measurement module (14), the junction voltage measurement module (14) is electrically connected with the printed circuit board (11) and collects the forward voltage of the LED lamp beads (10); the junction voltage measurement module (14) is electrically connected with the control module (13); according to the measurement result of the junction voltage measurement module (14), the control module (13) controls the output of the temperature control circuit (3) or the light source driving module (12).

4. A uniform area light source according to claim 2 or 3, characterized in that The application comprises one or more monitoring optical detectors (7), the monitoring optical detectors (7) are arranged in the shell (1) and are located on the inner side of the light homogenizing plate (4); the monitoring optical detectors (7) are photocells or spectrometers; the monitoring optical detectors (7) are electrically connected with the control module (13); according to the measurement result of the monitoring optical detectors (7), the control module (13) controls the output of the temperature control circuit (3) or the light source driving module (12).

5. The uniform area light source according to claim 1 or 2 or 3, wherein, The light source driving module (12) comprises two or more independent driving circuits; each driving circuit is electrically connected with a string of LED lamp beads; the LED lamp beads are arranged at intervals on the lamp plate.

6. A uniform area light source according to claim 5, characterized in that The light source driving module (12) comprises two or more independent driving power supplies (15); each driving power supply (15) is connected with one or more independent driving circuits; or the light source driving module (12) comprises one driving power supply (15), and the driving power supply (15) is connected with two or more independent driving circuits.

7. The uniform area light source of claim 5, wherein, The application comprises two or more different types of LED lamp beads (10), the different types include different powers and different spectrums; at least one string of LED lamp beads comprises the two or more different types of LED lamp beads (10) and the different types of LED lamp beads (10) are arranged at intervals; or each string of LED lamp beads comprises the same type of LED lamp beads (10) and the types of LED lamp beads (10) in at least two strings of LED lamp beads are different.

8. A uniform area light source according to claim 7, characterized in that The two or more different types of LED lamp beads (10) at least include a combination of blue light LED lamp beads and low color temperature white light LED lamp beads, or a combination of high color temperature white light LED lamp beads and low color temperature white light LED lamp beads, or a combination of white light LED lamp beads and infrared LED lamp beads, or a combination of white light LED lamp beads and ultraviolet LED lamp beads.

9. The uniform area light source of claim 5, wherein, The lamp panel includes blue light LED lamp beads and low color temperature white light LED lamp beads, and the blue light LED lamp beads are arranged adjacent to the low color temperature white light LED lamp beads; the light output is adjusted by the light source driving module (12) to realize uniform light output matched with the relative spectral power distribution of the CIE reference light source L41.

10. The uniform area light source according to claim 1 or 2 or 3, wherein, The housing (1) further includes a limiting diaphragm (5) arranged outside the light homogenizing plate (4).

11. A uniform area light source as defined in claim 1 or 2 or 3, characterized in that The printed circuit board (11) is made of high-thermal-conductivity material, and the printed circuit board (11) is bonded to the temperature control platform (6) by thermal conductive adhesive.

12. A uniform area light source as defined in claim 1 or 2 or 3, characterized in that A temperature sensing module (9) is further included, a sensor of the temperature sensing module (9) is in contact with the lamp panel (2) or the temperature control platform (6), and the temperature sensing module (9) is electrically connected to the control module (13).

13. A uniform area light source as defined in claim 1 or 2 or 3, characterized in that A light guide plate (8) is further included, the light guide plate (8) is arranged in parallel with the light homogenizing plate (4), and a light emitting surface of the LED lamp bead (10) is arranged perpendicularly to the light guide plate (8).

Images